Clank noise from Crank pulley & Lights flicker (video) Help!

Gentlemen, The weather is getting nice and I decided to do some work to my car prior to pulling it out for the spring. My interior lights were flickering prior to winter storage . I knew that my alternator bearing was wearing out so I decided to replace the alternator hoping to fix two birds with one stone. After I replaced the alternator... this is what happened... http://youtu.be/WVPycU_DVfE The interior lights still flicker (see instrument cluster lights and overhead light) and the engine appears to stumble in conjunction with the voltage drop. As you can see the voltage gauge it moving from 13 to 14v. Any ideas??? Added: After trying to troubleshoot my flicker issue.. I noticed a clanking coming from the crankshaft pulley region, videos below...

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Last thing touched is first thing suspected. Check the alternator connections and installation and mounting. Check too the drive belt is routed correctly and the tensioner's not stuck/frozen. If you find nothing amiss then perhaps the replacement alternator is well bad. But before you get all medieval on the replacement alternator check the things I listed above first. Oh, while you are there look very closely for any signs rodents have been at the car, the wiring and so on. Oh, the stumble might just be do to stale gas. Depends upon how long the car's been parked up. I'd not worry too much about the stumble unless the engine start showing signs of getting sick. Right now, at least from the clip, it doesn't even act like it has a fever. Also, with my car with a voltage gage upon a cold start the voltage reading approaches but doesn't quite reach the 14V mark. These gages aren't the highest quality so that bit of difference might be due to normal differences in the gages. Sincerely, Macster.

Macster, The problem existed prior to me replacing the alternator, the new one just intensified the issue. Belt and tensioners are good to go. Where are some areas that rodents my be attracted to? I replaced the main power cable that runs from the back of the alternator as well. The engine is clearly effected by the "dip" in power. The car has only been in storage for 2 months.

If it helps I had a jeep cj that did that. I replaced alternator,batt cables and redid the ground strap from the engine to the frame. The ground strap helped but found out eventually that I had 1 bad cell in the optima battery. Maybe try load test on battery?

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Thanks for the info, I just read that the battery could be the culprit on google. Where/how can I get it load tested? Autozone?

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YES. Also try O'Reilly's or Pep Boys (if you have these in your neck of the woods).

also Check the cable that goes from the alt to the junction block on the right side of the engine. The crimp/cable can overheat corrode and go bad.

Also Sears can do load tests. Voltage regulators can throw the same pulsing. Military trucks like to do the same thing sometimes for some unknown reason. You can try watching a multimeter but I'm sure its just going to be voltage going up and down. Bad case is your volts are OK but the regulator is thowing higher volts on and off. Watching your cars meter it seems you are getting higher volts than my puts out with new alternator on a new engine. Not sure if the gauges in all cars are created equal. Good luck finding the problem......I guess I should say good luck getting rid of the problem In any checks of the voltage with a digital multi-meter you want to watch for the voltage having a/c in it. It's spottable by watching the positive or negativ icon changing back and forth while you have the meter in the DC reading setting.

Update: Battery tested good. I even swapped in a brand new battery to see if anything changed.... Still same as before when the car is on. My next thoughts were to check the grounding strap on the engine... or maybe the ignition switch?

Hi Try changing the relevant fuses

I had the same issues when I first bought my car. Corrosion in the ground wiring. Check that before you spend $$$$ on other things.

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Two months is time enough for a pair of mice to raise two litters, almost... Rodents like cars. A car is a nice, dry, draft free environment packed with lots of tiny spaces/passages (err, well you know what I mean) that mice love and feel secure in. There's plenty to gnaw on too. I've see a few cars and the mice (or rats) will gnaw on wiring, hoses (rubber or plastic), seats, carpets. I've seen the rubber radiator ducting at the front of the car chewed through. I've seen the vapor line from the tank to the engine compartment gnawed through: the animal probably stopped when gas fumes starting coming from the line. Some times the damage causes engine symptoms and even a check engine light. Sometimes not. The creatures will shove nest and food litter onto the panels that are under the car. I read in another post you've eliminated the battery. That leaves connections as others have already pointed out. It is not enough that you check they're tight but that you disconnect the connections (watch the battery is removed so you don't accidently do something with the battery that electrically damages the car!) and visually confirm the connections are corrosion free, show no signs of looseness. That the symptom was there before the alternator and the battery is ok (I trust this is reliable info... a battery of one of my car's tested ok early in the AM after I had driven the car to the service department but the tested the battery later in the day and found it down enough to confirm the battery was bad.) You're looking at rodents, connections, maybe an ignition switch (you can move/wiggle this and see if it has any effect on the engine's behavior) or possibly water intrusion from blocked body water drains, or a leaking window seal or a windshield gasket. To check for water check carpets for any signs of dampness. Open each door and move it back and forth quickly and listen for any sloshing water sounds. Sincerely, Macster.

Another update: I removed and cleaned the main grounding straps for the battery and engine block. Also searched for any evidence of rodent damage under the dash, by the ECU and as much as a could in the engine bay. Afterwards, I ran the engine for 15 mins and the voltage appeared to stabilize slightly (around 13.8v). The flicker is less than before but I still think there is a problem elsewhere. Any other suggestions welcome Anyway, I also noticed a weird clanking noise from the crank pulley area. I will post some videos when i get home.

Clank with serpentine belt removed.... Rattle around 3k rpm occurs occasionally Clank from under car with serpentine belt Another clip from under car

do you have a stethoscope? if not a long handle screwdriver or wooden dowel even to press against things and stick the other end to your ear to help isolate the noise. I'm no expert but the first vid seemed to be noisy around that pully assembly, but then again i'm not standing there with the car physically. Does it have wobble/movement when moved by hand? Gonna go listen to all vids some more. worn/bad Chain tensioner maybe?

The noise doesn't sound good. You have to decide how much self-diagnosis you want to engage in. If something internal in the engine is acting up... you may want to think about avoiding running the engine anymore and instead let a pro diagnosis and advise you. In the last video clip I thought I spotted a shiny area on the edge of the crankshaft belt pulley. The picture wasn't steady/stable enough to be sure. Have you looked (it is hard but it must be done) to see if something may have dropped down (or a bracket or something else is loose) and is rubbing against the crankshaft pulley? Have you checked for any play/looseness at the crankshaft pulley? Sincerely, Macster.

No stethoscope. I tried to pinpoint the location with a long screw driver. No luck. You can actually hear the sound pretty well on first video without the serpentine belt installed. I touched the crank pulley while it was running and I didn't notice any significant amount of wobble. Would a chain tensioner make a noise in the front of the engine? My plan was to replace all three tensioners this Spring as well as the cam guides. Lets not forget about the flickering lights too!!

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The noise is not as loud as it appears in the video. I did check to play/looseness in the pulley and it seems to be solid. I will check to see if something dropped behind the pulley tomorrow and post an update. I did look at the last video and I think that shiny area is from the flash on my phone

I don't think the engine noise is doing the voltage problem unless maybe some cam chain tensioner is doing intermitent shorting or some fool thing. I highly doubt that. Anyway since you are chasing down connections there is one on the bottom of the car where the power line to the rear couples together. It's a bolt together splice down there. I've never looked at it but imagine its a pain to get to unless you have a good lift. You could try the game of diagnosing while changing what is turned on or connected. I was wondering if the a/c is on which would have the compressor on even if the heat is on. Make sure you turn the compressor off. Two things I'd go after is the radiator fans and compressor. Fans can be disconnect and a/c turned off. If the a/c is on it tells the fans to run last I knew. Also check on any audio amp located in the trunk. Were the lights still doing the pulsing with the belt off? If so that eliminates the alternator. On the a/c side compressor have a switch for engaging the belt drive. Maybe that system is screwing around. I seemed to of noticed the engagement screwing around after my compressor fried. If your refrigerant is low it can have your compressor alternating between on and off since it hits air pockets shutting the system off then back on when fluid is present in about the same cycle you are getting with the lights.

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I agree that they are two separate issues. Is there a way to test the variocam solenoids? The a/c is not on for sure, although I do have the fan hack switch wired up for cooling when I need it. I did not care to look if flicker occurred without the belt on. (I will check tomorrow as well as the amp in the frunk)

Could it be a loose spark plug?

Hmm.. i had loose plugs before and the sound was not the same. It is worth checking again. Thanks for the idea. Tomorrow i will post updates after inspecting the crank pulley, spark plugs and listening with the stethoscope to pinpoint the location.

I looked in the catalog and can't see a diagram of the cable route. But it does go along the underside of the car under the plastic. I think it was mentioned to be around the transmissioon. I'd say use the search function but for some reaso I just glanced over a seperate page of the site and didn't see the search icon. Oh well, dinner time.

this is just a copy and paste from ehow..... Fixing flickering lights in an automobile 1 Check the alternator/generator with a voltmeter. The most common reason for flickering lights is a worn out alternator, as one of the three rotating plates that generate electricity wears out. So as the unit hits the "dead spot," the power wanes, causing the lights to flicker. The voltage should be over 13, ideally over 14 volts. Automotive parts shops will likely have a machine to test the alternator for free. Replace the alternator if it fails to produce more than 13 volts, or tests bad. Most alternators since the 1970s have internal voltage regulators, but for external models this unit is mounted close to the alternator and can cause part failure. 2 Check for loose or disconnected ground cables. Some on-board engine computer systems are sensitive to loose connections, affecting the ignition system as well. A ground strap or cable is on the engine and sometimes on the transmission. Many electrical items on the car, including the ignition system, will depend greatly on these ground connections. Wobbling bolts or intermittent connections can cause the lights to flicker. Tighten these grounds, as well as the primary battery ground wire. 3 Check for loose or disconnected ignition wires. On most cars, there is one wire for each spark plug. When they come loose, up to 70,000 volts of electricity can ground out every time the wire is fired by the distributor. This can cause severe light flickering and may damage sensitive electronics. Read more: How to Fix Flickering Vehicle Lights | eHow.com http://www.ehow.com/how_5058944_fix-...#ixzz1nD6yc2HO

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Thanks, I actually just saw this yesterday while I was surfing Google for some answers. I am going over to my car in a few hours and I will post some updates after. In case I did not mention before.... the lights flicker while the ignition is in the "on" position while the engine is "off" BUT the symptoms intensify when the car is idling.

that leads me to think wiring/battery terminals loose and/or corroded, bad ground etc..... , not alternator. and intensifying when car running means more current flow than static battery juice. same source of problem whether car running or just key in on position. can't wait to hear what you find.

Update on electrical issue: I looked at the major wiring harnesses, battery cables, relays again. I tested the battery while the car was idling and it showed 13.75 to 13.92 volts. Appears to be normal to me. I took the car for a drive and the voltage is smoothing out. At idle i now see the largest fluctuations on my gauge and the engine idle flucuations as well. Update on clank: I tightened all the spark plugs again. #2 and #4 were the only plugs slightly off torque. No changes with the clank. I pulled the serpentine belt off again and used my stethoscope on the entire motor. The clank is CLEARLY coming from the crank pulley. I inspected behind the pulley and it was clear minus the slight dampening of oil. I am stumped. I took the car out for a nice drive (5-10 mins) and the sound is still there. I wonder if the sound is coming from the crankshaft and I am hearing the sound amplified on the pulley??? Ideas at this point??

Not sure where the voltage regulator is but try giving it a "technical tap" also known as banging on it. If it's a regulator with points in it they some times get corroded which lowers read voltages then the thing alternates between making up for the lower voltages. I've never seen my voltage gauge go as high as yours that I recall. A bad cell in a battery won't show as lower voltages till the cell is completely shot. But before going all the way bad it will lack the amperage needed and pull the rest of the cells amperage available down hence the battery gets a load then the power isn't available. But if it's a bad cell you should be seeing reduced cranking power sometimes.

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The voltage regulator is attached to the alternator which is brand new. I actually replaced the battery with a brand new batter yesterday and it didn't make a difference. I have not had any problems starting the car either.

I picked up a Durametric reader real soon after getting my car so that things like this would be easier to chase. I suggest getting one of those so that if anything is showing up it might give clues to where the bad info or parts get noticed. You can also read live reports on what outputs are from darn near everything in the car.

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I hear ya. One of these days I will pick up one of those. I am more concerned about this clanking noise coming from the crank pulley.. Strange...

I would remove certain main wrie terminals like grounds, clean and reinstall. Also the positive cable from battery at both ends, clean and reinstall. Key ignition switch might be suspect too. I have a 66 mustang and years ago the lights etc would do what you have, well it turned out to be the headlight on/off switch was over heating so it was cycling bright/dim as it cooled and heated up. Probably not your issue but thought I'd share.

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Yeah, I think I will order a new ignition switch next week. I did remove, clean and replace the cables for the battery and engine. Any thoughts on the clanking noise?

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I will do some reading and thinking on that and let ya know. Wonder if you gave Jake Raby at flat6 a call or shoot him an email he might be able to help too. He is after all the guru!

Regarding the noise. I would start with the "simple stuff" and move to the "worse cases". Perhaps try rotating the engine by hand, can you hear it make the same noise? Remove the flywheel pulley and see if there is something stuck behind it or any wear marks on the back side. Very very briefly run the engine without the flywheel pulley, does it still make the noise? Does it matter if the engine is cold or hot? You're certain it's not coming from the oil pump console just beneath the crankshaft? Then we move on to the less happy stuff... 4-6 chain "slapping" or hitting something (perhaps 4-6 tensoiner is busted?) What are your cam deviation readings? Could it be a spun rod or main bearing? SpeedrII had a method to test for a bad rod bearing with engine in car, it's in another recent thread, I'll dig it up later if you can't find it. Perhaps the thrust shims have given way, is there excess lateral play in the crankshaft? (not as easy to test unless you remove the transmission). Other than that my guess is something might be hitting something inside the bearing carrier. I hope the problem is in the "simple list".

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If you're sure the noise is not coming from the pulley because it is loose, or cracked/split, or has something rubbing against it, if you're sure the noise is coming from inside the engine, and if you're sure that something at the other end of the engine is not making the noise (say a flywheel or some kind of clutch problem even if it is just a noisy clutch disc on the input shaft spiines, even a noisy transmission input shaft) the only idea I can offer at this time you should think about turning the problem and the diagnosis over to a pro unless you want to continue to tackle this yourself. The noise will almost certainly not go away on its own and whatever is going on will almost certainly get worse. Sincerely, Macster.

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I assume you are talking about the crank pulley not the flywheel? The noise is more noticeable when the when is warm. I will remove the pulley this weekend or early next week and inspect the area as well as the oil pump console. What leads you to believe that it would be 4-6 tensioner versus the other two? If you could dig up that method to test for a spun bearing that would be excellent. Ill post updates as soon as I can. Thanks!

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I'm not positive that it isn't the other end of the engine. I will inspect in the next week days and post an update.

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Yes sorry I meant crank pulley (front of engine). Maybe/hopefully it's something as simple as you dropped a bolt while doing the alternator R&R. The long 4-6 chain from the IMS tube right below the crankshaft is on the same side as the crank pulley, therefore the reason why I might suspect that as a possibility. Perhaps if the chain has too much slack, or other chain/sprocket issue the noise would be apparent there. Here is the post regarding checking rod bearing play: https://rennlist.com/forums/9299331-post4.html

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Sounds possible... I will remove the 4-6 tensioner soon and post my results... what are the wear limits on the tensioner? make sure it isn't collapsed?

Pulling the 4-6 tensioner is not simple, you have to remove the air conditioner compressor, also the engine should be locked at TDC. If it were me I would start with the easier stuff first. For example removing the crank pulley is not very complicated.

+1 for what Logray and Macster already said! Hope you get it sorted out.

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Just so it is clear I was not advocating removing the crank pulley only suggesting it might be the source of the noise if it was loose, cracked or ?. Sincerely, Macster.

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The engine has two IMS to exhaust camchain drives. One for each cylinder head. The drives are located at opposite ends of the engine. I haven't checked but I believe for Bank #2, cylinders 4-6, the IMS to exhaust camchain drive is located at the serpentine/accessory drive end of the engine and thus the guides/tensioner that controls this chain is there too. The #1 Bank, cylinders 1-3, have its IMS to exhaust cam chain drive located at the other end of the engine, and of course on the other side. For a spun bearing if you found no metal bits in filter housing oil or the filter element and an oil analysis turned up no bearing metal in the oil, the odds are very high the engine does not have a spun bearing. A 'test' is to measure the oil pressure. A spun bearing will represent a big (internal) oil leak and oil pressure will almost certainly be down from nominal. How much down I do not know. I have never tested a healthy engine's oil pressure and have no baseline. You have to be careful you don't go too far afield in trying to isolate/diagnose this noise. The first rule of working on your car is do no harm, not to yourself, to anyone else, but also do no harm to the car. Sincerely, Macster.

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Correct.

I am not showing any significant drop in oil pressure that I am aware of. I changed the oil prior to storage and only found 2-3 tiny silver flakes. (could have been from the drain plug) Based on that info and what Macster mentioned above, it seems unlikely that I spun a bearing. (I hope) Tomorrow, I will be removing the crank pulley, checking for noises by the transmission and removing the 4-6 tensioner for inspection. BTW: I changed my user name from r1de23 to RPMulli in case no one noticed

We are waiting from you... Robert 2000 C4 Iris Blue Pearl

UPDATE: I decided to head straight for the a/c compressor in order to remove the 4-6 tensioner. What a PITA! I realized that there are fuel lines connected to the back and wrestling with it for an hour! I had to remove the TB, power steering reservoir, and y-pipe in order to access the lines... Finally got it out and I noticed some wires sticking out of the block. I found out that the oil level sensor is located below the compressor and I broke it off! I guess I need a new one. I pulled the tensioner out and it appeared to be in decent condition. What do you think? I also found a wire (yellow) that was leading from the starter solenoid that was chaffing. This may be the culprit to my electrical shortage/pulsing. Pics attached....

I forgot to add... the clanking noise is not coming from the transmission side of the motor only the crank pulley region.

There is some scoring on the tensioner, which usually is recommended to replace if there is scoring. Is it very easy to depress like the spring has broken? You can also put it in a tub of fresh oil and pump it until it gets stiff to make sure the internals are clean. Still though if it checks out ok, that was just an idea... and good you checked, but might not be the source of the noise. Did you remove the crank pulley? Yes the lead that goes from alternator to starter to jump point in engine bay is often corroded and can be the cause of a weak electrical system.

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The wire actually goes from the solenoid to the main wiring harness. How do you define "easy"? I can push it in with my thumb. I am going to replace this tensioner regardless... I am not pulling that silly a/c compressor again. I recall there was an article either here or renntech regarding the updated tensioner and the old style. Can you use the new style on the old chain guides/pads? PS. I did not remove the pulley. I didn't want to remove the pulley while the tensioner is out. OR do you think it would be okay?

Is this the updated p/n for the 4-6? 996-105-188-01-OEM

Oh you mean the starter solenoid lead... I would clean it up with some sandpaper, reattach and cover with some dielectric grease. I meant actually the larger main power wire that attaches below that one, is can become corroded and the source of many electrical woes. You should be able to press in the tensioner. But it shouldn't just collapse in without force, likewise the piston should not pop out (of course if it already did that would have already caused a problem). It sounds like it's OK, but if you are going to replace it sounds good too. As for the correct P/N to use, TSB 1551 only applies to the IMS paddle tensioner. For the 4-6 tensioner, use whatever the latest superseded part is. It requires a 12mm hex/allen socket instead of the 32mm socket. If the tensioner is out, you can remove the pulley as long as it is already locked at TDC (set pin). But I wouldn't rotate the engine with the tensioner out to get it to TDC so you can remove the pulley, wait until you have that tensioner back in.

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Oh okay, I thought that TSB applied to all 3 tensioners. I will go with the p/n that pelican has then. The piston was definitely not collapsed or sluggish when I pressed it in. Yep, the pin has the pulley locked at TDC. I will try to get over to my car tomorrow and pull the pulley off for inspection. In the meantime I will order my new parts and hopefully they will fix my problem.

Also the WSM says to replace the pulley bolt any time you remove it. If the sound is coming from the inside, and the tensioner looked OK, chances are the noise will still be there. Hopefully there is just something wedged in behind the pulley.

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Yes, I am hoping it isn't something internal...

Parts ordered.. ignition switch, oil level sender, 4-6 chain tensioner and bolt for the crank pulley. Should be here by Mid-next week. I will post updates regarding the crank pulley tomorrow.

Sorry in advance for the sobering look at this... Even if it is internal, think worst case, you have a salvageable core. Which is much more valuable than an engine that is toast. I think Macster said it best, perhaps in this thread... if it is internal, the engine should not be run or if it is run only in the hands of a pro that can diagnose what the problem is. When you run the engine with these types of noises and something goes kaboom you are left with nothing in a lot of cases. Unless you are feeling adventurous and want to tear into it yourself. Another thing you might want to consider is dropping the sump plate. There are a couple largish holes from the sump into the crank/bearing carrier area which perhaps you could "see" where the noise is coming from, you get a view of the mid section of the crank/rod/bearing carrier. But even then if you see or don't see it might still mean tear down. I hate to be fatalistic about this stuff, but this is the reality of the situation, I'm still hoping for something simple. Another thing that could be done without totally tearing the engine apart is removing the oil pump cover to inspect, although I think the console requires the engine to be dropped, and even then you can't see a whole lot, only the other end of the ims tube, maybe there is something caught in the oil pump? Doubtful. You don't really start to see the internals until you pull the heads and pop off the 4-6 case half. Also boroscope might be a good idea, but if the noise is clearly coming from the bearing carrier/crank then you are probably looking at rod, crank, or bearing noise.

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Lets be optimistic here...

Update: I pulled off the crank pulley and I may have found the source of my noise. There was a bolt that was jammed between the block and the bracket below the pulley. Since the noise was intermittent, it is possible that the bolt would dislodge and hit the pulley then fall back into place. Anyone have any idea where this came from? FYI- I dumped power steering fluid down the front of the engine while removing the reservoir.

Broad head on the bolt makes me think its for holding platic in place. Not sure otherwise. That power steering fluid eats rubber and such except the plastic its stored in of course. Maybe some degreaser spraying down where the stuff got on would help keep from any bad resulting to hoses and rubbers.

Wow! I didn't think this was gonna have a happy ending. Congrats Ryan,go buy a lottery ticket.

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Yup, its cleaned.... Hey im not out of the woods yet, I have to install the new parts and start her up!!

Come to think of it it appears to be like some drain plugs that have plastic washers between the bolt head and tank body.

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I can't tell by looking at it.. maybe a piece of the old air intake? It has rubbery plastic on the head almost like it was a stud of some sort.

Yahooooooo! That's great news!!!!!!! Great work. Not sure where that bolt came from, but it looks trashed for sure. You might want to check the condition of the flywheel pulley. They only cost about $70 or $80 to replace. Cheap insurance from it blowing up and destroying your serpentine belt leaving you stranded. You can lay the pulley on a flat table and see if it is like a potato chip, or if there is excessive scoring, or if it is out of round or cracked.

I'll bet that the "bolt" is part of vibration damper. There is one just below the throttlebody, or should be. Looks like this... http://www.directindustry.com/prod/n...84-404429.html

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I'd just ask the dealerships service department about the wear abouts of something like that being. Or one of the club members might know exactly where to look.

Part 12

Nice diagram and thanks for making it easy to understand.

That is exactly what it looks like it could be!!

Does the main seal look ok? Hard to tell from that pic.

It looks fine.. i could not tell if it was leaking since i dumped powersteering fluid all down the front of the engine. Atleast it should be easy to replace when that time comes.

Update: I received a new oil level sender and ignition switch today. Installed the switch and the flicker is still there (ignition "on" and engine "off"). I am running out of ideas on the flicker, maybe I could test each fuse to see if there is a draw from a specific area or component. I installed the oil level sender and realized I could not put it back in the way I pulled it out. The passenger side intake plenum needed to be removed otherwise I would snap the new sensor in half trying to bend it in the hole. Simple job with the a/c compressor removed. Also, I noticed a vacuum actuated solenoid on the pipe that connected the right and left plenums. This solenoid moves a butterfly valve, what is its purpose? Anyway, the tensioner and crank pulley bolt will be here Wednesday.... I will post my next update then.

Thats the resonance flap, changes the intake vacuum tuning at different engine speeds.

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Doesn't it create some turbulent airflow in the plenum? Why not just leave it open all the time?

Page 190 through 192 for a read on the engineering behind the resonance flap. http://books.google.com/books?id=Raa...page&q&f=false

Thanks for the link, I should pick up that book!!

Just saw a post in local porsche forum, about charge problem's. Car was 997 turbo, but I think that the same wire could be the problem in your case allso. Check that cable for voltage drop. It seem's that the same wire is used in all watercooled engine's (akun + napa = battery + terminal)

The above wire was the one that I replaced that solved many of my electrical problems. Also did you replace the entire ignition switch mechanism (the more expensive fix?), or just the cheaper fix (the $10-15 part)?

I replaced just the electrical portion and I replaced that large wire leading from the alternator last year.

Update: Finally got my last parts in the mail. I installed the 4-6 chain tensioner and the noise appears to be slightly quieter. I wish I knew how long this noise has been going on for because it is easily hidden by the sounds of my exhaust. Could the noise possibly be caused by something in the head/camshaft region? I plan on replacing my chain guides later this year. Meanwhile, the car drives perfectly fine.

Sorry to hear the noise is still there. If you've pinpointed it to near/behind the crank pulley area then chances are that's where the problem lies.

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Quick question, I want to run the engine without the pulley on. Should I just pull off the pulley at TDC then run engine, reinstall the pulley, turn motor to TDC with bolt, break torque then retorque??

yep that should work!

Logray, are there any known failures of the smaller bearing on the opposite side of the intermediate shaft? I know its not the roller type.

I hate to cast a shadow on the situation... best to keep a good attitude about it, but odds are... I haven't read of any ims tube front end failures (aside from "rebuilders" re-using parts that should not be re-used), but certainly there are those who have more experience than I and will have a more seasoned opinion/idea. Yes I've had my engine apart and back together again but that doesn't make me an expert, by any means. The only way I would guess that end of the ims would fail is due to extremely low oil levels/pressure (which could be due to a blockage or just neglect). The bearing is an oil film, and is one of the very first places that get lubed after the oil pump in the oil path. Perhaps the 4-6 chain sprocket on the ims tube is lose or damaged? My bet would be more on a spun bearing, perhaps chain/sprocket noise, or maybe something (obstruction of some sorts perhaps upstream or) is caught in that area, causing a lack of lubrication. If it happens every "so often" maybe that is more evidence towards a chain/sprocket or rod bearing related noise, since those would be periodic, whereas an IMS bearing (front end) or main bearing which might in theory be more constant. You could pull the front main seal and drop the engine down a little, but there is very little room to "see through" the sides of the crank and case. Likewise if you pull the oil pump and have a look at the pump and front end of the ims shaft, very little room to do so without dropping the engine... and even then you can't have a look at the cam chains or sprockets without pulling the 4-6 case half off. I hate to say it might be time to bite the bullet, but if you keep running it with the noise you might risk creating a situation that is not salvageable (meltdown), or figure on running it until it blows up, take the loss, and source a used engine perhaps (they seem to be dropping in price)? It's a tough call... sorry about the bad news again.

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That's a plain (hydrodynamic) bearing just like the main/rod bearings. Extremely rare it would fail. (My info is the front main seal occasionally leaks though.) I've been away from this thread a bit but IIRC you reported no metal in filter oil or filter element. If my memory is correct a bearing failure is, to me anyhow, an unlikely explanation for the noise you are hearing. 'course you'd probably then turn around and ask what is the source of the noise right now I have no idea. One thing that comes to mind is sometimes when one gets to a dead end he needs to turn around and look anew at things he dismissed earlier. Every step forward is based on the decision that what is being considered right now is not the source of the problem. If this decision is based on faulty data, or faulty testing, or faulty reasoning, or faulty 'net advice (ahem!)... Sincerely, Macster.

the ims front bearing is in the oilpumpframe. Just remove catalysators and the backplate that hold's engine, and drain coolant. Should be done about 4h.... I have a good used oilpump. I changed it when I was hunting the starting noises...

Another thought, there has been reports about broken spings in the oilpump pressurevalve. Have you checked that? So, before you teardown the whole engine, check the oilpump first.

Thanks for the info guys. Today, I will pull the pulley off and run the engine in order to REALLY pin point this noise using a stethoscope. Unfortunately, I am at a transition point in my career and I don't have a permanent garage to drop an engine. I will post my findings this afternoon with a video.

One potential source could be the IMS shaft moving fore and aft -If the bearing retaining clip was not fully seated .

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That is a thought... wouldn't I see the crank pulley moving forward and aft?

No-I think the only way to verify the shaft isn't moving is to either pull the the transmission -flywheel and IMS flange or possibly by removing the oil pump. Logray can probably shed more light on that .

If the bearing lock ring wasn't in place and the bearing wasn't driven all the way home and the center support nut wasn't cinched down maybe? It's an interference fit though with the bearing, and it might have worked it's way out of the tube a little??? (I guess meltdown would happen shortly thereafter) Probably more likely explanation for your theory would be the center bearing support isn't fully pressed in the back side of the bearing, and/or the center support nut isn't torqued properly causing the tube to float forward/aft... and maybe the noise you are hearing is chains slapping (should be grinding really) against the case on the 4-6 side (I guess that would prob. be more of a constant noise though). You might have similar noises on the opposite end if this is the case. If you remove the oil pump and coolant console you could grab hold of the ims tube and see if there is any forward/aft play in it. There should be none (well, maybe a few .000x", whatever the ims bearing will allow). Also inspect the condition of the oil pump hex driver. It would probably be easier to drop the transmission and inspect the ims flange if you suspect this, although once you drop engine and trans both are just about as easy. Before tearing into the engine though, (assuming they are both dropped), certainly it would be worth pulling the transmission/fw and also oil pump to eliminate the "easy" fixes (relatively speaking). If the thrust shims in the bearing carrier failed you would have forward aft movement in the crankshaft, particularly if you have the car on stands and someone operating the gears, clutch mechanism, you would have better potential to see the crank pulley move forwards/aft (but that doesn't have anything to do with the IMS tube floating around). Try to get a better isolation on the noise, top/bottom/front/sides/etc. We are all speculating wildly here... and as Macster pointed out so well, the Internet guessing game can often lead you down the wrong path...

Sorry, I misunderstood what dcdrechsel mentioned. Of course I would not see any play in the crankshaft... I would LOVE to eliminate everything that I could possibly do before removing the engine/transmission.

So, 7 pages and no one suggested that noise could come from the exhaust system? I tryed to search vid's about bad catalysator's but could not found on that would work...

Gentlemen, We may have a breakthrough... I pulled the crank pulley off and the sound stopped. Very strange... I used a stethoscope around the area and I don't hear anything abnormal. I put the pulley back on and tested it with and without the belt. The same noise came back. I am seriously thinking about just buying a pulley and being done with this. Thoughts??

Ahhh more good news. Have you inspected the area around the pulley and the pulley itself to see where it might be clicking... maybe the TDC lock pin boss, is there a bolt that's not tightened all the way that it could be contacting? I'll look through some pics. Or perhaps the pulley just has a crack or something and when it's spun around it clicks. Is the nose of the crank OK? The fact that you found an old bolt behind the pulley makes me wonder if there is some damage or still a piece of it lodged somewhere. Try a new pulley? Is the locating pin in the nose OK? Looking at that area there's not a lot for the pulley to come in contact with unless perhaps a case bolt is loose, or the tdc pin boss is damaged

Meanwhile, as I try to diagnose my electrical problem...... I pull all of my fuses out except the instrument cluster (needed to see the flicker) and reinstalled them one by one. I was not able to pinpoint it to one fuse but it appears to me that it is something on the engine electronic side. Here is a list of the fuses that were installed and the flicker continued: B1 (instrument cluster), B8 (central locking/alarm control unit, engine electronics control unit, Tip control unit), B10 (instrument cluster, diagnosis, headlight adjustment beam), C1 (engine electronics), C2 (ignition, fuel injection, oxygen sensor heating), C3 (central locking/alarm system, power windows, inside lights, sunroof) C4 (fuel pump).

I used to have the same flicker and low voltage problem, but it is gone now. My cars electrical system is perfect again, charges at 14.2-3 volts and once charged never drops below 13.6. No flicker. Here's what I did. Replaced: Battery Positive lead from battery to fuse box behind psngr footwell. Positive lead from fuse box to junction box above transmission. Positive lead from junction box above transmission to jump point on engine Positive lead from jump point on engine to starter to generator Sanded all exposed terminals on engine and wiring loom and protected with dielectric grease. Negative lead from engine to body (sanded/wire wheel body contact) Negative lead from battery to body Alternator

Alright, I am about to post a video for you. I did not trust my table top so I inspected my pulley on a granite counter top instead. There appears to be some wobble in the pulley and I bet that with some slight movement in the crankshaft combined with the wobble it is hitting the pin boss on the block. although no signs of contact visible.. Check it out...

Looks like a potato chip to me. My old pulley does that too, but only very very slightly, much less than yours. It has a slight radial wobble, but is very very slight. That line where the boss is looks normal, mine has that too. If you want I can mail my old pulley to you today, and if it works out give me $40 or something for it, otherwise if not mail it back to me. Let me know. The new pulley I bought is pretty much perfect, not out of round axially or radially.

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That sounds like an idea. Right now the pulley goes for $107 on pelican. What is it going to cost shipped to 19335?

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Is there a possibility that it could have something to do with the ignition coils?

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Hey Ryan, sorry been busy just got your PM. I can mail it to you tomorrow. I think you can get a new pulley for about $75 or $80 from sunset or sonnen (shipping not included). I mean the passenger footwell. The MAIN fuses are in a small plastic box behind the dashboard bolted on the trunk wall. The postive lead from the battery is a short wire that bolts direclty into this fuse box. Then distributes the power to various spots in the car. Then there is a very long long power cable that goes under the center console out a grommet in front of the transmission on the top of the well to a small junction box above the bell housing (psngr side). You can test your igntion coils with a multi meter and inspect for cracks, here is the misfire troubleshooting guide with the proper ohm readings (page 6). http://www.renntech.org/forums/index...ttach_id=24613 In my case, I'm on my second set of coils since the car was new. Flickering went away after doing the work I outlined above, same coils before/after flickering.

Awesome! I had no idea that there was a junction/fuses located there (shop manual online doesn't show it). This may be the source of my electrical issue. IIRC, a few years ago the weather stripping on the cowling below my windshield was torn and it allowed water to leak onto my floor (passenger side). I will check it out tomorrow. PS: It appears no one else in the forum wants to touch this thread!

I would lean towards something exposed to the elements, the main fuse box is pretty well sealed up, as are most of the other points in the car, aside from the ground on the engine, and the engine power mains. GL, that fuse box is a pain in the back to get to, would be surprised if that's your problem. I took the "take no prisoners" attitude and replaced all of the major power leads. It's a huge pain in the neck and back to replace the long power lead from that fuse box to the junction above the transmission. And then the wire from there to the engine. Don't know if I would have done it if the engine and trans were not dropped.

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Exactly.... I suppose I am going to have to twist my back while upsidedown the same way when replacing the ignition switch?

That box is impossible to get to without taking out the blower for the a/c. Today I took advantage of the 70 degree weather and had to wash the car. Tomorrow I will test my ignition coils for proper resistance.

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If you washed the car and didn't drive it to dry out the brakes the rotors have likely rusted up some. When you go to move the car the brakes may issue a pop as the pads break free from the rotors. If you have the parking brake on when the parking brake 'shoes' break free from the rear hubs. Also, be sure you use the brakes hard enough -- do not come to a complete stop! -- to remove all of the rust. Once you've done this then you can bring the car to a stop and the hot brake hardware will not interact with the rust dust to possibly cause pulsing brakes. Sincerely, Macster.

You can get the fuse box out without removing the blower. My back is not happy for it, but it is possible.

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Did you drop it down? If so, how? I could only slide my hand in there.

Once you remove the bolts and primary wire from the trunk side, you can push the box from the trunk area (via the studs) into the passenger compartment. Then from the footwell, with a little care the box will slightly deform the plastic and carpet surrounding the a/c blower and wall when you pull on it, being careful with the wires, it will "slide out" of the stud holes and you can pull it down into the footwell. It's certainly not and easy thing to do, and I would hate for you to go through the trouble unless you intend to replace the long cable from there to the junction point in the transmission well above the bell housing (which is an entirely different story/pain in the ***). Chances are that box is totally sealed and "factory fresh", given it's location, unless perhaps the car was flooded.

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This electrical issue is bugging me. I want to start over and explain what and when this flicker occurs. (Ignition switch - off) As soon as I open my car door the overhead light flickers (not a consistent pulsing) almost as if a wire is loose. My battery volts are a constant 12.53-12.56 without a key in the ignition at the battery terminals and each fuse in the fuse box in the drivers foot well. (Ignition switch - on + car running at idle) The instrument cluster lights continue to flicker as does the overhead interior light when I turn it on. As you can see from my first video on my dash the voltage gauge fluctuates as well. The car also seems to stumble slightly in conjunction with the voltage drop. (Ignition switch - on + driving) The volts gauge is stable (around 14v) and the engine stumble is gone. Since the voltage is stable at the fuse box what could cause the voltage/power to fluctuate between the box and the component (ie interior/cluster lighting)? Bad ground for the fuse box? What grounding points are associated with the box? depends on the component? I was reading the wiring diagrams and the ground point locations in the car are not easily identified in the manual. Any ideas where GP1-GP14 are located to include the "Ground Electronic" and "Body Engine Ground"? I already checked the battery ground and ground wire located on the 4-6 bank from the engine to body.

Another update: I checked the resistance on the coils. They read .06 ohm across the board which is in tolerance. I was able to look at the grounds attached to the frame behind the dash (GP3, GP4 and Electronic ground). No corrosion on either. I am about to start the car after I put the coils back in and pull the fuses one by one. I NEED to pinpoint this electrical problem!

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Remind me again, did you replace the entire ignition switch assembly (~$100-200 part) or just the cheap part? $15 part. There have been reports of people not having their ign. switch related problems fully resolved (problem keeps coming back with cheap part) until the entire assembly is replaced. This sounds like a bad regulator or high resistance somewhere. But I know you replaced the alternator and also had it tested later right? One way to rule out some primary wires is with a good quality set of jumper cables. You can "bypass" various primary leads and see if the problem goes away. This is normal. I don't think the box itself is grounded. Also just because the voltage is steady, I wouldn't rule out the main power leads or main ground cables (or even alternator/regulator). GP1 to GP14 are all throughout the car. Did you replace that main engine ground strap or just test it's resistance (the one at the engine). Pulling the fuses is a good idea to isolate, unless of course the problem is the ign switch. Also, you can inspect and clean the two main ground points on the engine, one on the rear of the 1-3 head (front of car) and another on the front of the 4-6 head (rear of car). Those grounds are secured by a small bolt and a ring terminal, with a bunch of ground wires coming out of it.

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I replaced the electrical portion of the ignition switch ($15 part). My key certainly turns better in the ignition now. The 4-6 ground strap is on the forward part of the head (checked). I guess the 1-3 is to the rear (not checked). Also, I took a different approach and ran the engine without the serpentine belt. The voltage gauge is steady.

Alright, I think we have a breakthrough here.... I just decided to swap my old voltage regulator into my new alternator and VOILA. My voltage gauge fluctuation is fixed. Although the lights flicker when the ignition is off slightly. Its progress atleast..

Maybe that points to an around or in the alternator wire having a bad connection. It's still there just moving things made better contact. Some guys give up and pull on the wire which is bad. Wire can look great but wire especially old wire doesn't stretch while the plastic cover will.

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I just replaced that big wire from the alternator last year. I think they are two separate problems since the flicker existed prior to storage. The voltage fluctuation occurred after I replaced the alternator.

If the alternator is bought from porsche parts department I'd think they would look at replacing it to eliminate a bad alternator. At least they would over here after doing a diagnostic. Hawaii takes care of their owners. The guys working as mechanics buildup their own 911's and the service department manager besides a porsche he has a 67 chevelle SS in burgandy so he's cool just for that fact

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I typically avoid the stealership, but it sounds like you have a good relationship with the place in HI. BTW: The alternator I bought is aftermarket. I swapped the new voltage regulator with the old Bosch regulator I had (since the bearing was shot in the alternator I replaced).

Crank pulley update: I installed the pulley that Logan sent me and the sound it STILL there. I believe it must be sound that is amplified by the pulley through the crankshaft (hence why I cant hear the noise while the pulley is removed). I guess I will have to wait until I drop the motor to fix other items to diagnose this issue. Anyone have any other thoughts at this point? I know this thread is long!!

Check for axial and radial play in the crank. If it's a thrust shim issue the crank will push forward and aft (but might not do it as much or be as apparent until the transmission is removed).

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Didn't you have a thread where you were checking for crankshaft play?

Yes "crank pulley wobble" or something like that. But checking the axial play is tough, like I said with the engine and/or transmission in car. You can measure radial play with a dial indicator with engine in car. You can try to push/pull it forward/aft by hand but it's hard to both get a grip on it as well as get a measurement. If you can "see" it move forward and aft by eye I would say there is a problem, but you might not be able to see it, and there still could be a problem (only revealed by close measurement.

Is the sound the same with the clutch pedal depressed ?

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TBD.. I'll let you know when I check the crank for play tomorrow or tuesday.

Update: I checked for play in the crank, none. I pushed in the clutch pedal to see if the sound stops, noise is still there. I went to take of Logray's pulley and removed the bolt/washer. After sitting there for a minute, I was playing with the bolt and washer in my hand. Come to find out that the washer was very loose (worn) on the bolt and it made the same exact noise when the pulley was installed on the motor. The noise has the same metallic tone as in post #14 (first video). Compare both videos. Below is a video of the motor without the crank pulley and the bolt/washer. Vs. I think that the slight wobble in both pulleys combined with the worn washer is somehow moving the washer against the shank of the bolt. The sound is seriously identical and I did torque the bolt to spec. Thoughts?

Can you use an articulating extension mirror and see if something is maybe wedged inside the the threads? Can you thread the bolt all the way in the crank nose and can you feel any resistance when threading by hand? If you turned the pulley bolt 90 degrees after the initial 37 ft lbs I would be very surprised if anything is moving around, it should be totally secured by the bolt and torque spec, with no movement whatsoever. You're certain the nose on the crank is free of burrs, imperfections, as is the pulley mating surface, so the pulley is perfectly flat against the crank. The locating pin is not loose. I don't believe the washer could get "thin" enough so to speak to where it wouldn't allow the bolt to secure the pulley, I think there might be enough threads past the length of the bolt + pulley to prevent that situation. It might be worth looking into though. My old pulley definitely wasn't true, not as bad as yours - but it didn't make any noise on my engine, wish I would have sent you my old washer too. Still, maybe it's worth a brand new pulley, washer, and bolt before you drop the engine?

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The bolt does the thread completely into the crankshaft without anything else attached. There is a decent amount of axial play while the bolt is 1/2 to 3/4 threaded in (may be normal). The noise is the exact same with either pulley on too. I had someone rev the engine up to 3k and the rattle noise increases with the engine rpm. I was listening to examples of rod knock and spun bearings last night and my engine does not make the same noises. Wouldn't I hear the noise from somewhere along the middle of the engine from underneath?

Listening to the first video without the pulley it's really hard to make out but it almost sounds like the noise is still there, albeit very faint, the higher pitched tinny sounding clicking. Then with the pulley on perhaps it is amplifying the noise as you pointed out earlier. There is a main crank bearing just an inch or so behind the front main seal, and a rod right behind that. The right end of the pic is the front main seal bore. You're right though your noise doesn't sound like a spun bearing to me.

Generally a rattle is more associated with the chains and related hardware-although a catalytic converter can also rattle . .A rod knock is pretty distinctice .Since the crank does not appear to have excessive play the IMS has to be suspect .That being the case don't know if it is a good idea to run the engine .

Yeah Ive been studying the internals of the engine lately. Great teardown pics on Pelican! It has been tough since all my of my equipment is in storage. I ran out and grabbed my rhino ramps and I am going to lay under the engine and see if I can pinpoint a faint noise elsewhere. Updates to come. The noise does get significantly louder around 3k rpm. Isn't that when the variocam solenoid actuates? It doesn't seem valvetrain related though.

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Agreed, it does sound chain related... Why would the IMS be suspect? It is below the crankshaft... I put my stethoscope directly over the center of the pulley and the noise is clearly coming from there. I'm sure I already mentioned this in the thread but the noise only occurs after the engine is warm.

The crank can certainly transfer noises from elsewhere. When I had my crank at the machine shop, he tapped on it with a hammer and it rang like a bell. If the noise is not related to the way the pulley mounts up to the crankshaft, then I would tend to agree the pulley is just amplifying the noise from wherever it is coming from, perhaps even from the other end of the crank.

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Okay, so I crawled under the car and listened from start-up until reaching operating temps. The seems to be a scratching type noise (sounds like spinning a spoon along the edge of a metal bowl) coming from the flywheel/ims region. There isn't a distinct tapping as heard on the crank pulley side but something is going on. I upgraded the IMS bearing 2 years ago. Maybe the pilot, ims or throwout bearing?? Something with the clutch or DMS? This certainly may be good news because a spun bearing would be a PITA.

If you don't have a stethoscope, take a long screwdriver and press it against the IMS bearing area, cup the other end of the screwdriver around your ear. Hear the noise more clearly now?

I hope it's clutch related .To answer your question on why the IMS is suspect- if the IMS shaft were moving fore/aft and banging the oil pump that could create a strange sound (I think).From my motorcycle days I remember chains doing some wild oscilliations if a sprocket was wobbly .

Did you check the oilpump already? You can remove small cover from the oilpumpframe to see the gears. Draining the coolant is not needed if you just remove the small cover.

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I was using a stethoscope

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Will oil spill all over the place? I am gearing up for an engine drop. I will be heading over the harbor freight for am engine jack

I'm not sure if the pump is below oil level? Might be... So draining the oils first would be good idea.

Remove part 25 to check the gears

I was about to say, have you pulled the oil pump? I think you will have to support and remove the rear cross-member to get access.

Fellas, I think I am going to bite the bullet and drop the motor/transmission. This way I will have access to everything including the ims/flywheel. Don't worry another thread will be created so the forum can keep up-to-date on the fun!!

Any update! bye bye Robert