Engine Noise

My brother just gave me his 99 carrera that he has outgrown due to 5 kids. He had lost interest in the car and lost the key so the car sat in his garage for the past 1.5 years. Never had a day of problems with the car and when it was parked everything was ok. Checked oil, put a new battery in it and the engine started right up, but with a kind of knocking sound. The car idles at about 900 steady and the engine sounds healthy except for this noise. Tried putting it in reverse and pressing gas and the noise just got louder. Decided to turn off and maybe get some ideas as to what could have happened. Checked the oil didnt feel anything unusual in it. Is it possible that the oil is no good and not lubricating vital engine parts, or could it be the dreaded ims bearing? Thanks for your reading and any possible solutions.

Could be an ignition coil or bad plug. Worst case piston slap.

Thanks for your input? Is there anyway I can check for the ignition coil or bad plug? Worst case if it is piston slap does that require rebuild or motor replacement?

Quotes source post: 10228143

Pull the plug wires off one at a time to check for bad plug wire. Rebuild highly recommended for piston slap.

It's probably a hydraulic lifter that needs a bit of time to pump up. Common with engines that sit for a long time. Most of them will get quiet after getting it up to operating temperature. Let it idle for 15 min. And see if it fets quieter. A bad coil should triger the check engine light, the lifter won't.

lifters / chain tensioners have leaked down after sitting for 1.5 years. Start it up let it sit at idle. The noise should settle down. Change the oil...

oil is old, I would change it.

Thanks for all the input. I will change oil and see what happens? Any suggestions as to what type of oil to use initially?

0-40 mobil 1 to get the lifter(s) up then change it within 500 miles to ... your favorite.

Quotes source posts: 10228096, 10228359, 10230037

So sad. I don't understand this concept. Listen to Imo. The dude knows his sh*^ Mobil 1 5W-40 per my local Indy, unless of course you want to join the darkside and come over to the Joe Gibbs DT-40 side

The car is in the islands, so if there was a Porsche dealer there I would simply take it back to them. Wasn't having any luck with the Mobil 1, but there is big castrol and valvoline dealer, will see what they have comparable. I am in for the long haul, because this car is too hot to have sitting in the driveway. I did go ahead and order 2 cases of the dark side oil along with the oil filter adapter and other service parts just to have on hand. Really tempted to drive her and see what happens but don't want to turn a simple problem into a new motor. I have searched and searched on what this noise could be but it simply seems as though as I read somewhere a test is worth a 1000 opinions. If all else fails will have to send back to either dealer or independent Porsche specialist, any suggestions?

Quotes source post: 10230389

A knocking noise suggests something more than just collapsed lifters arising from lack of engine use that will self-correct with some engine idling with the noise going away as the oil warms up. If the noise has a knocking characteristic to it and you are not just mixing/misusing adjectives this suggests something more serious than relatively less serious lifter bleed down. Thus I would err on the side of caution and flat bed the car to a qualified Porsche tech and let him hear the noise and pinpoint its source and then he can advise you.

As imp000 said Let it idle for 15 min and see if it gets quieter. Change the oil first though. Does the noise get faster with rpm It`s probably due for spark plugs anyways. Have it brought in the a mechanic who can also borescope the cylinders while the spark plugs are out. They can also check the coils to see if they have cracked and rusted out. New coils and plugs are wear items anyways and the extra hour for the mech to borescope the walls it well worth it. With my engine, I had a soft tick which would go away after it warmed up. Also using heavier oil made it louder. I also noticed higher and higher oil consumption. Now 2-3 years later I need to add oil every week and the noise doesn`t go away it get quieter but still is there. Borescope showed cyl 4 was scuffed, 5 out of 6 cylinders had oil pooling in a very short period of time.

Yes the noise gets faster with rpm, and it seems to momentarily disappear with an increase in rpm but as the rpm idles the noise is back, and I wouldn't call it a soft tick. Does the motor need to come out to change spark plugs, coils and check with boroscope? I already ordered dt40 oil, oil filter, gas filter, air filter so I will get a set of spark plugs and coils. What are the best plugs to use? Concerning the coils, is it better to get from dealer or does someone make a better aftermarket set. Thanks Again

Can you isolate the knocking from below (or above) with a long screwdriver? Heads or block something pulley driven (unlikely).... You can roll the dice on a oil change, but if the knock's down deep in the block I'd shut it down and ship it to a qualified indy or dealer....

Borescoping requires positioning the pistons, I personally can`t comment on how that is done but pulling the spark plugs does not mean an engine dr�p. But if your replacing plugs anyways it`s saves on labour rates since they they are removing them all ready.

When my water pump bearing failed, I got a knocking sound. Sounded horrible. Don't drive with a knocking sound until you know where it comes from. The Dealer took one listen to mine and diagonosed a failing water pump.

Quotes source post: 10231383

I'd go OEM -- check with SunCoast for your parts. I'd isolate first before wasting money on R&R. You can access all plugs from underneath car without dropping engine, you might find it easier to pull wheels. 99's do have some block issues. So check you oil for coolant and vis-versa. You might isolate which cylinder it is coming from by either listening with a stethscope on each cylinder area -- or try pulling the connector to each coil pack until you hear it change of go away. It is still possible that its a chain tensioner and the chain tension is loose. they could have bled down and/or their internal orings have dried. The chains can slap the tensioner rails or the case in extreme situations. Good luck, Mike

If you decide that you won't do harm to the engine by restarting it, try running it without the belt - that will answer some questions before randomly throwing parts and cash at it.

The dt40 oil and service parts haven't arrived yet, but I went ahead and removed the belt and did a QuickStart and run and the noise was still there. I had two local older mechanics listen to the noise and they both said independently that it sounds like the lifters. Hopefully, that's all it is. One recommended using a Lucas oil stabilizer to help with the lifters, but I think that Porsche doesn't recommend additives to th oil. If that isn't recommended does porsche recommend any additives that might help? Thanks again. Can't wait to drive it like a stole it.

How long did you run it this time?

I doubt it is recommended by Porsche -- but you can try some seafoam to see if the lifters quiet down and then change the oil out. There have been cases where the lifters wear against the lifter tray -- I haven't seen that. But since you are dealing with a car that has sit for a while it's possible it's a lifter that has gone soft or caught some debris and isn't pressuring up just quite right. Mike

Only ran the car for a couple seconds, without the belt, no more than 30 seconds at most. Just waiting on the oil change to see if it is in fact the oil and lifters. Called Champion Porsche in fort lauderdale where the car was purchased and they wanted 20g's for a new motor, wtf. I could buy another car for that.

Quotes source post: 10239914

Porsche doesn't recommend any oil additive. Some sources have told me that Swepco 502 additive seems to quiet down engines upon startup that aren't used much. I tried the stuff a few oil changes in both cars but noticed no difference. But my cars see use every other day or so. Really if the engine doesn't quiet down to some acceptable level with the right oil in it about the only "additive" that can help at this point is money. Add money to the tech's hand and get the engine fixed. It's sick. If the noise is a lifter that has bled down and needs to pump up again all you can do is make sure the oil is fresh and of the right type and start and run the engine. Let it idle until it is about as warm as it will get idling. Then you can raise the rpms to say 3K and hold for a few seconds then release the gas pedal and let the engine return to idle. At 3K rpms the oil pressure should be near max and with the oil hot (or nearly hot) and if a lifter has just bled down this ought to (no guarantees!) have the lifter pumped and quiet. I'd be a bit concerned if the lifter wasn't quiet before it came to the 3K rpm step. However, there have been a few cases where this last step, or something like it is required. I would not drive the car though preferring to do this on the driveway -- or on a lift with a tech under the car giving a listen for any sounds of something getting worse -- and with the doors open and so I can hear the engine very well. If at the first sign of some other noise or the engine starts acting up you can shut off the engine very quickly. If you are on the road you might due to safety reasons not be able to shut the engine of quick enough or you might be tempted to limp the car home or restart the engine after shutting it off. But you need to be sure what you hear is from the lifter area and not from some other place. If the noise is from some other place it can arise from a problem that more engine running can only make worse.

This is driving me crazy, wish there was a Porsche tech on island that was familiar with this car. Oil and service parts should be here next week, will change and see what happens. Also will look for Indy in south Florida that I might be able to fly in and let check car rather than shipping car back to dealer. Got some price quotes from them, just don't understand why anyone would own a Porsche once warranty is finished, I could buy another low mileage 996 for one of the quotes. The saga continues.

Quotes source post: 10240449

There you go. You didn't run it long enough as some have suggested. It's funny seeing people worry over potentially nothing due to all this fear going around.

Quotes source post: 10242535

That's what I think too. Reinstall the belt the waterpump is spinning and let it warm up. Don't worry about changing the oil, just let it idle and get nice and warm. Posting what if scenarios is easy, anyone can list every possible reasons for a noise and this can scare the crap out of those that aren't mechanically inclined. If the engine wasn't knocking before it was parked then its extremly unlikely that something broke from sitting.

As you've indicated Imo000, the lifters can take some time to get them working 100% again. I've had this happen to me as well after letting my car sit for 2-3 months in which the oil all drained to the bottom and needed to be circulated enough in and around the lifters for them to work 100% again. In my case, I think it was around 10 min or idling/revving. I wouldn't panic just yet...

With all the focus on the oil, I was just wondering about the quality of the gas in the tank if the car had been sitting that long...

Odds are high that the only real problem is that it has been sitting for a year and a half. Some ticking at idle is pretty normal for these cars. Especially when cold. Do what others have said. Put in the right oil with no additives. Also, I hope you put fresh gas in it. You don't was to shellack your fuel system. Start the car and let it get good and warm. See if it gets quieter. If so, you are good to go.

Quotes source post: 10243242

+1

1 noisy lifter You Tube another one different car You Tube Not a lifter noise. Sounds like IMS or Piston slap, You Tube

Thanks for the videos. Unfortunately, I couldn't figure out which video sounded more like my engine noise but my girlfreind insists that it is the lifter video. I tried to switch it up and she kept picking the lifter video. I will take a video of the noise and post it. Thanks

Not sure if this will work but it is a link to the noise that my engine is making . I think this should take some of the guesswork out of the equation. You Tube Thanks

Is it as loud as the video when revved up? Remote diagnosing anything like this is nearly impossible. You or someone that knows engines will have to do some basic testing. I still feel that one would be getting the engine up to temperature. At some point you'll have to stop asking the same question over and over again and do something to find out what is going on.

Quotes source post: 10244924

+996 I gotta go now onto WebMD and have the guys over their look at my dookie sample to see if my kidneys are ok.

I think the engine is hot because the fan is running. The last part did not sound like a lifter. It almost sounded like something more harsh is going on than excessive VT clearance from lifter. Did you try w/o belt? Whatever it is, your beyond hoping it will fix itself.

Wait a minute, that last clip is actually the engine in question? If it is, I misread it and I'm sorry. Sounds like a valve train noise.

One thing to take into account is where the OP lives. If he lives in a frigid climate and it's 5 degrees and the car has 15wxx oil, then it's gonna take longer for the oil to warm up. Based on the fan, OP did you run it for awhile to bring the temp up yet?

It does sound like a lifter that is not pumping up at all.

You really need to get the car to an expert. While the noise sounds bad it sounds too bright to be a valve lifter. That it got louder/more distinct when you are at the back end of the engine down low reminded me some time back someone reported a ticking noise that turned out to be some hardware (bolt or something) in the engine crank pulley. A tech with the car in the air and a stethescope will have the source of that noise located and once that is known then what to do becomes clearer. It is time for someone to get his hands dirty.

The fan comes on as soon as I turn on the engine and runs for a couple of minutes after the key is off. I haven't run the car for more than 2 minutes so far, still waiting on the new oil and service parts to arrive before I really wait for the car to warm up. After reading the responses I am looking at either flying in a specialist or sending car back to Fl. Can anyone recommend a service i enter in south Florida

There is no one around you that can work on it? A good mechanic should be enough.

Quotes source post: 10245744

Honestly to me, it seems like you are jumping the gun and letting paranoia get the best of you. It seems like you are planning out all the doom and gloom situations over potentially nothing at this point. my $.02

when you had the belt off, did you turn by hand all of the accesories and the idler pulleys? My motor was making a horrible noise like it was self destructing and it was only a bad idler pulley bearing. It's always best to eliminate the easy stuff first. You mentioned the fans coming on, which seems odd in that it takes a really long time before mine come on when the car is just sitting idling...what's the temp gauge showing?

Maybe it was a CEF. The engine still needs to be taken apart. If the noise is indeed a collapsed lifter(s) its probably damaged something by now.

I had my 996 runnig yesterday (it hasn't ran in a few weeks) and it made the same noise but at a much lower level. Once it warmed up and I revved it a little it went away. To put it in perspective, if yours noise level was 10 then, mine was 3 but the interesting part was that it sounded exactly like in your clip. Recorded video sometimes amplifies the sound so things can sound a lot worse than they are in real life. Have you let it warm up yet or are too scared to do aything?

Thanks for the input guys. I really don't know how long the oil has been in the car but I know it has been in there at least 2.5 years, it is a synthetic but I don't think its the mobil1 0w-40. I see that the oil plays a major part in these type of engines. The mobil1 0w-40 oil and service parts should be here on thursday. Hopefully, this weekend I will be able to change oil and drop oil pan and see if anything has broken and there is debris. If this car requires an engine tear down or major work, I will just sell it because to spend 20K in a car on a motor, that might break again is just dumb to me. These engines just don't have a good reputation on the internet and the price of the used cars shows this. I would rather invest in a newer model turbo that isn't prone to such engine failure. Thanks

Quotes source post: 10258020

I thought you were going with the magic JG Dt-40 oil? Also dropping the pan doesn't seem totally necessary if you haven't even had a chance to run the engine up to operating temps. You're better off IMO sending some of your oil to Blackstone for oil analysis. It can pick up more data than you can see with your naked eye. Also tear open your oil filter for visual inspection. If you're this scared and nervous already without even doing a proper diagnosis, a Porsche really isn't for you IMHO.

I am really short of patience, the JG Dt-40 oil won't ship until next week sometime. If I knew where to get the JG oil in Florida what have gotten it already. Just sent someone to FL and they picked up filters from the dealer and oil from advance. I ordered 3 cases of JG just to have on hand, if its all that I might try in my vette. Not really scared or nervous, its just a lot of post on different forums saying how unreliable the motor is and how it just self destructs without warning, even if you service and use right fluids. I beg to differ, about oil analysis, it can only tell me about the problem I obviously have, I think it would be more practical for preventative measures. Its either lifters, piston slap, or something broke loose. I figure any debris will be in oil pan, like metal fragments, etc or in oil filter and I can then look up in motor. Parts and service arent as easy as in US, so if this is a problematic motor, I will minimize my losses in this car and invest in a 911 turbo, that seems to be more reliable. Why throw money after bad. I can get a motor rebuilt for 7-20k depending on who does it, or spend 20k at dealership for new motor that might do samething. This car was pampered, but driven hard thats why it only has 40k miles since bought brand new, even though it was hibernation for past 2 years. Thats just the down side of not being in US, there is 70% duty on car and car parts, no dealer and no porsche specialist. Don't want a car that is problematic, reason why my brother bought car new from dealer. I had a brand new Range Rover supercharged, car spent more time being fixed than driven and always had something going wrong. Had to change supercharger 3 times, dealer covered it but had to fly technician in from dealer to fix whatever went wrong at my expense to maintain warranty. Test drove new 911 turbo at dealer in FL during christmas, and it was crazy nice. I just want something that when I turn the key, no stress. I wanna drive not be a mechanic.

Sounds like you already made up your mind so, just sell the car as is and get one with a warranty. Let a DIY-er pick it up and figure it out. Doesn't sound you have the know how or confiedence to own an out of warranty car anyways and that's ok. My '99 has 201000 miles on the original engine, so they do last.

No, I haven't made up my mind but I am just looking at worst case scenario. Right now just pissing in the wind. Will have to get hands dirty and see what's going on. I hope that I am just over reacting. It was very encouraging to know that IMo000 has over 200k on motor and going strong. IMo000 have you done any major work to motor? Is that 200k on the original motor? Thanks again

Quotes source post: 10258550

Still wondering about the gas in the tank. Did you drain the old fuel and put in fresh 91+ octane? Just using the wrong brand of gas straight fronm the pump can make my engine knock. Good luck whatever you decide.

Quotes source post: 10258550

I bought the car as a non runner. The original owner drove it until one of the vario cam tensioner pads broke and made the chain jump. This bent 6 exhaust valves. I then fixed this and installed a few new parts to freshen it up. There is a thread on this at the Canadian forum. Do a search and you'll find it under "I dragged me home one of these". The rotating assempbly is untouched and besides the 6 new valves and tensioner pads, the rest is original (new gaskrts and hardware were used where it was required). It's been back in the car since last fall. Some would consider this major work but in reality it's only moderate as the case was not split. I encourage to do the work yourself but if you are not confortable with it, I can understand.

Quotes source post: 10258739

It wouldn't knock at idle. If the gas is bad, it would either run or not when idling. This is a single source tapping noise.

Thanks for your words of encouragement and inspiration. I do feel the gas in the tank is old but I feel as though this is something more than lifters or old gas. I have the oil and oil filter now. Rather than speculating I will drain the oil and drop the oil pan and see what I find. I will then have a better idea as to what is going on. I am hoping that it is something simple but only time will tell. In the islands the only gas we can get is 89 octane. Does porsche or anyone recommend any additive to preserve the life of the gas and or improve the octane rating.

Quotes source post: 10259727

I don't really get your logic. First off you haven't even run your engine long enough so how "do you feel" it's not the lifters? Secondly, If you were going to drop the pan regardless before putting in new oil, why did you wait for the oil to come in? You could've just dropped the pan first while the new oil/filter was in route. Lastly, what are you hoping to see or not see dropping the pan? And what will that exactly do except let you know there is no debris there? You'll still have the noise regardless. Also if you are dropping the pan, do you have the correct pan gasket sealant to do the job correctly? Or do you have to order that and wait a few more days? I love it when people come on here for help but ignore half the suggestions by experienced members and try to formulate their own theory. It doesn't bother me any, hope you get it fixed without getting an ulcer or growing a few gray hairs.

I will have to agree with Alpine003 above that dopping the pan is a fruitless exercise at this point. Screening the drained oil and cutting open the oil filter will tell you all you need to know. If it's a mess in there then you know it's toast. As for 89 octane, the noise I hear on your video is not pre-ignition. That doesn't mean you can't or shouldn't run a additive, it's just not the source of your particular knock.....

Additives won't do anything to the gas. One octane point is actually only 0.1 octane. So if you add the amount recomended on the bottle, you'll go from 89.0 to 89.1. If the gas is bad, either drain it or if the tank is empty enough, fill it with premium.

Quotes source post: 10266883

I believe OP mentioned Premium wasn't readily available where he was at hence the inquiry about the additives.

Here is my engine noise, noisy at 1100 rpm. RPM range in the Video is from 800-2000

Thanks jumper5836, that seems to be the same noise that my engine is making. Did you ever find out what was causing that noise. I saw earlier that you said it went away after warming up and heavier oil made it louder, and it drinks oil, is the engine still running like that or did you have it repaired?

No repairs. It's been like this since 2008, it used to go away after being warmed up but not anymore. I had the cylinder borescoped and the mech said I had a scored cylinder and that 5 of the 6 cylinders had abnormal oil pooling. Meaning that 5 of the 6 are ovaled. I've driven it hard at the track in this condition many times, even today after 3 months storage. Drive it hard any it just keeps ticking. No issues other them it burns oil. My dyno under current condition and had other similar or newer 996 3.6l with same results the same day on the same dyno.

Jumper, why the delay in dropping the engine before it possibly causes more damage? Maybe its not that bad of a repair if mech is wrong. That noise would drive me nuts.

Quotes source post: 10271133

I bought a 996 Turbo as I didn't want to miss another season at the track. The C4S really won't be driven until a I can afford the engine rebuild. Hopefully this summer. I only brought it out of storage to do a drive clean test to renew the license plate.

SO TeamSadistic............. We are still waiting for the final answer.....2 weeks ago you were asking questions and questions...now we would like to know the answer......like many others ( AOS story) you just disappeared....

So correct me if I'm wrong guys but if the noise gets louder or faster with increased rpm's then it is more likely coming from a piston? If it doesn't then it could be valves?

No, it can be either or something totally different in the engine. Noises like this are tricky to diagnose. Last week was working on an engine that sounded like a really bad camshaft tapping. Turned out it was an idler bearing for the serpentine belt was coming apart and the pulley was rubbing against the casting webbing of the block.

Thanks Imo000. Ran the car for about 20 mins yesterday after storage. Had a slight tick as well but did not notice if it went away after it reached operating temps. I'll have to check it out again.

Soft ticking sounds like the lifters. I agree, get it out and get the oil good and warm (that will take driving it around for as much as half-and-hour; oil warms up more slowly than coolant). If the ticking stops, it was the hydraulic lifters. If it doesn't, then it's something else. Unlikely to be the IMS bearing, and a plug or coil misfire would definitely trigger a CEL. Not feeling piston slap -- could be, I suppose, but that's usually more of a clatter than a soft ticking and unlikely that a spun bearing resulted from just sitting.

Ran the car for about 15 mins again today and even after that there was a slight ticking. Took it out for a 15 min drive and voila! No noise.

Quotes source post: 10328732

Great news but IMO its pretty typical for Porsches that sit for awhile unused to have some lifter noise and a reason not to be alarmed at first. If the car was put away fully functioning, it can't all of a sudden just break from sitting for the most part. Any updates from OP btw?

Sorry guys, I have been too busy with other projects and was a little bummed with what I have learnt about these engine problems. Oil and service parts have arrived so I will probably attempt some service and troubleshooting? Quick question, fuel level is really low so is it okay to fill up with regular fuel and add a fuel stabilizer or should I use vp race fuel? Should I fill tank completely or 3/4 or what? Thanks

Quotes source post: 10348810

Use a regular non ethanol fuel if you can and add the stabilizer. They old way says to fill it completely. I think this was so the tank didn't rust I don't think it matters for our new cars though.

Alright guys for everyone that read the post, I recently posted what happened to engine on a post titled island update. I got the dt40 oil, put in high octane fuel, changed all filters and stated motor, sound actually began to go away, after couple minutes pressed gas and kaboom, no more noise, no more engine. Bottom part of connecting rod came thru case. Not familiar with how engine is built, but can engine be repaired?

Quotes source post: 10526715

Bummer. Engines can be repaired but probably not this one. Busted case is generally an engine killer. Time to look for a replacement engine.