Suspected Catastrophic Engine Failure (w/Video) 996 3.4L

Good morning everyone, I seem to have had a bad stroke of luck with my 996 this weekend, par for the course really. Back story on this car, its a 1999 M96-01 3.4L Carrera 2 with 137k miles on it, Recently just repaired a cracked head issue with an all new cooling system, Costa-Mesa R and had machined the head (and did a brilliant job). new IMS bearing (Pelican Single row, installed correctly per instructions). New Air Oil Separator etc etc the list goes on literal thousands of dollars in parts. The engine was retimed by a porsche Master tech, who happens to be a friend of mine locally, using the correct tools. 2200 miles late, a bad sounds start to happen, see video below. 996 engine noises part 2 - YouTube 996 engine noise - YouTube [ My current thoughts are leading me to believe the $4,000 dollars I spent on rebuilding this thing the right way recently have just now become a scrap core of metal. Any suggestions you can provide on what you think the problem is would be appreciated. I am having it flat bedded back to my garage this week. Provided links for the youtube vidoes incase the embedded part did not work.

I suggeat stop running the engine and tow it back to the shop you had tye heads done. Best case is one of the accessories such as water pump, alternator, idle pulleys, etc.

Btw, not sure it means something but I saw the idle tensioner pulley is kicking a bit which may indicate a changing load on the drive belt.

How's the oil pressure when it runs? The metallic sound would indicate a bad rod bearing, squeaking noise would be from ims shaft if the bearing failed. When you have a bad rod bearing you hear more of a knocking noise, when you have ims failure it's squeaking noise. These are the only 2 things I can think of with the engine running and still working. If the oil pressure is still good check the ims. If you have a 99 996 you should have a dual row bearing, you said you replaced it with a single row?

I would not run the engine. Two items: 1. I thought the MAF was on the intake and the intake appears to be removed, how is the car even running without the MAF hooked up? 2. You state you have a 99 and the IMS bearing was replaced with a single row, I thought 99's have double row bearings?

My bet is on ims.

Begin with taking off the belt and not start the car, check each pulley by hand and listen for noise. If you dare start it again, with the belt off, ask a friend to start the car, keep it running only for like 20 seconds and shut it off again. Meanwhile it is running with the belt off, you can listen if there is any noise. This will make the water pump, ac, dyno and servo not run, thus excluding those faulty. I did this and it was the belt that was old and porous not gripping the pulleys, not that that is comparable. Also does it behave in this fashion when the airbox is in with the MAF connected?

The squeak sounds like a bad idler roller bearing. The other behavior as others have commented on, and with which I have to agree, comes from the MAF being removed. Avoid running the engine. Put the thing back together and get it flat bedded back to the shop. There the source of the noise will be ID'd. I make no promises but I don't think it is an engine failure. If it was the engine would sound worse.

I did all the work myself with the help of 3 mechanics over the course of several weeks, one of which was a certified Porsche Master Technician from a local dealership. I put in the Pelican IMS, Part Number PEL-IMS-1, I always had a whurring sound from the engine after I did the update, we used the LN Tool Kit to install the IMS. (Hats off to the LN guys for doing an incredible job with that tool kit for install). I am having a racing friend tow the car back to my garage. I did have the oil light flicker on for a second but oil pressure was still doing great. Idle was 20psi at the least I dont remember specifically but right when I had saw the light and looked up at the gauges before I shut it off while I was driving it was between 20-30 psi.

In that case, as Arne suggested, remove the drive belt and hand spin all the pulleys first. Then I think it makes sense to check the obvious such as oil/coolant intermix, oil filter and oil pan for debris. The noise sounds external to me but it's hard to tell from the recording.

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The pelican bearing can be used in the 99 with spacers

Water pump w/ metal impeller?

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Oh...., I will have to check my documentation ( I took pictures of the build just incase I decided to sell it later on as proof of the things I fixed). Are you talking about a spacer of the IMS bearing forward in the tube or a spacer on the shaft to meet the flange

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I really don't understand the logic for anyone with a dual row to go this route personally...

^^ Right there with you. Replacing a fairly stout part with (what appears to me) a less robust retrofit seems insane to me.

I have not looked at the pelican bearing in over a year. They no longer use spacers, but for the dual row they have a "spiroloc" ring.

It would be very interesting to see the condition of the Imsb dual row that was removed to accommodate the single row. Odds are there was nothing wrong with the duel row.

I havent been able to do any further diagnosis as of yet, Transporting the car back to my garage tonight and will report back with the findings after I have removed the serpentine belt, which I am not suspecting to be any sort of good news finds.

Got the car home, pulled the serpentine belt off, fired it up for a second then shut it right back off, fiddled with all the pulleys nothing that clearly make the knocking sound, the knocking sound is still there, but the squeaking sound is gone. I have my Porsche master tech friend coming by next week and we will probably start to pull the engine down out of the car, or at the least drain check and possibly analyze the oil, and go from there. After the recent rebuild I already went through for repairing the damaged head, I am beyond dreading pouring more money into this engine.

Sorry to hear it, best be cautious in these matters.

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Valves making more noise on new seats? This may not be a bad time to keep an eye on the oil, maybe get a monitor like that IMS guardian deal, and put a few hundred miles on it?

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With the noises its making, I believe my best bet is to remove the engine from the car, inspect everything I can, Send the oil off to get analyzed Pull the oil pan, see what I can there. Pop off the IMS cover check the bearing, Remove the head I hadnt had serviced before so I can split the case and take a look at the rods/bearings. Has it been done before when an engine knocked on one of these to pull it apart, replace the rods, put new rings on the pistons, and reassemble, break in correctly and go about your merry way?

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Neither can I. It's like replacing a fat rear tire with a skinny donut.

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No, if a rod is damaged the crankshaft is damaged. To access the rod bearings you must remove both heads & fully disassemble the engine.

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Well and then you have the fun of putting it back together and testing it out again... From what I'm told rod bearings really start to make noise when they are really loose, and that can be tested without taking them apart. If they are snug then more than likely they are good. I know that's a bit of a sloppy way of doing things, but part of this is if it aint broke don't fix it, and if the bearings have been happy and working there is little reason to take them apart and mess around with them. IMO and could easily be wrong. [edit] and I really do feel the pain of the OP. It sucks when you put a lot of work into something, and a crap ton of time putting it back together, only to find out that there is an issue and the issue more than likely is behind a crap ton of work pulling the engine back out. Happened with (on a much smaller scale) my motorcycle. Got it all together after a hot-rod rebuild and it had a knock - just blaming it on loud valves after adjusting the jetting, measuring the rod bearings (thankfully didn't have to pull the engine), colder plugs, double/triple checked the timing, decompressed it a little, and it still does it - although it is more happy now. So yeah, it sucks, but that just happens sometimes when working with this stuff. [edit 2] I really doubt it's scrapped and that the engine is junk at this point. If it was put together correctly and everything looked at as it was going together then I really have doubts something evil and dark would just pop up and ruin it. Sucks that it's going to take more time, but I would be looking more on the bright side.

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1st You need someone that knows these engines well to listen to the noise with the engine running & properly diagnose it. If you post your location maybe someone can give you a referral.

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I feel sorry for the OP - but I think all this preventative maintenance is sometimes over done.. The advice from rl and my Indy have pushed me toward oil change and breakdown maintenance., just keeping an eye open., if I get a cel get it checked pronto- I could drop $$ 2-5k and do the preventive list - I like running factory parts as long as possible. I have a 99, if had a newer car or hated my money - I may be more into the "list". Wishing luck to the op -

Hey Stevespeed. I came over this video: . To me that rattle sounds similar to yours. He had his chain tensioners replaced. After starting up his car he had this rattle in the engine for like 10 minutes. Here is a thread on it he calls himself SpawnyWhippet . Read from post #24 and down. Hope this helps.

I agree with removing the drive belt to isolate the sub- systems. Thats the problem, 4K won't scratch the surface of a comprehensive build for this engine. After pulling the drive belt, if the noise persists, shut it down and don't even think about restarting it.. All that racket may as well be 100 dollar bills burning, because thats what every second is doing to your wallet. Don't run it to death.

Usually by the time the connecting rod or main bearings starting to make noise they already spun and the point of "just needs replacing" is long gone. Keeping an eye on the oil pressure should give you more warning of a worn bearing......but sometimes things happen so quick that unless you are glued to the gauge, you will not notice this in time either.

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Flat6, I incorrectly spoke as to what I was meaning. This engine previously had a cracked head failure, so the $4,000 I spent was in repairing that head failure. Including the machining and repair of the head (similar to way the Dharn did his) Buying the correct tools to time the engine, replacing the entirety of the cooling system minus radiators, as well as a clutch. I at the time did not believe the bottom end of the engine needed to be touched as it ran fine before I noticed the coolant and oil intermix and pulled the engine. I have pulled the drivebelt, check momentarily for noises on a quick start up, the squeek went away but the clank is still there. I will update as I get around to pulling the engine and pulling the oil pan and everything else. Do you have thoughts as to what it could be? Theories so far either Rod bearing has spilled, Tensioner in the timing system has failed or when I replaced the intermediate shaft bearing, the new bearing failed and is causing the noises. I am hoping it is not crank/rod related as these units are non-machinable, and no oversized bearings exist.

In that case, if you had coolant in the oil, you are probably seeing collateral damage from the cracked head. This is a huge concern anytime we make a repair. The engine has to be qualified for a repair. Sometimes I spend two days assuming the engine is guilty, before I'll agree to qualify it for repair. Coolant in the oil doesn't do any internal component any good.

Steve, Don't despair. Some crankshafts can be saved. Just have to find the 'right' place to do the work and have only superficial damage. If there is oil in the coolant, it would be wise to assume all the coolant hoses are contaminated and should be replaced preemptively. An engine issue that may condemn it is ovality/taper of the bores.

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When I pulled the oil there was no coolant in it, the crack had seemingly only gone one way (dont really know how that is possible) but when I had drained the oil initially we used a clean pan to determine if that had happened or if there was any internal damage during that. We found the oil to be just a bit dirty with no signs of coolant, just a deep brown color, with no metal shavings, we ran a magnet through it as well as high intensity flash light to determine if there was any reflection from the potential shavings. Fortunately, there were no metal shavings or coolant to be found. Yes there was coolant in the oil that is what prompted a new water pump, new thermostat, new hoses, new reserve tank, new oil cooler hoses, a proper coolant flush, all radiators were dismounted and cleaned throughly, new hoses were placed in the car, and then ran on water with detergent for a while then replaced with Pentefrost Coolant.

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Yes there was oil in the coolant, that is what prompted a new water pump, new thermostat, new hoses, new reserve tank, new oil cooler hoses, a proper coolant flush, all radiators were dismounted and cleaned throughly, new hoses were placed in the car, and then ran on water with detergent for a while then replaced with Pentefrost Coolant.

That's a bummer. Sounds like you did all the right things to address the cracked head and intermix.

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Tried to at the least, in one engine pull did Air Oil Sep, Clutch, PPlate, Slave IMS Cracked Head Repair, All gaskets that mattered, All the timing chain guides that were reachable Every Seal and O-Ring possible, 3 oil changes in the 2200 miles it did work to ensure nothing bad happened to the engine... to have something bad happen to the engine.

I feel your pain. Let us know what you find...hopefully it's something repairable.

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sorry to hear your pain - hope the remedy is easy on the wallet - best of luck.

Hello everyone, small update (i know it has been some time). The car since the incident has remained parked and dormant at my shop. A while back I decided to run the engine for just a quick moment. I noticed that the clattering sound had greatly decreased and there was still a clank but it was not with engine time. It would be out of phase with what an engine failure sound should be. Tonight the car is going up on to the hoist and the engine removal is starting to happen. I will keep this updated with what I find with Oil analysis (visual possibly sending it out) and so with what happens from here. I leaning towards either the IMS is still the issue which if it is I will have to seriously evaluate if I am up to the task as I hear once the IMS goes back the IMS Shaft is essentially not reusable. The main theory is that something in the timing system is the issue whether it be a tension or a guide. Here to prayers and hopes that is not the crankshaft / rod bearings.

Update, Car is now resting on my hoist, Oil drained into a nice clean new oil pan so I can send some off for analysis with no cross contamination with my other vehicles dirty oil. Oil did not have many metal shavings in it but was a bit sparkly so I decided to check the oil filter... then my heart sank. Looks like there is a fair amount of shavings in the oil filter and after reading alot of FlatSix's posts, I am questioning the re-usability of my block. I am now questioning even pulling the engine to go through it yet another time, sending the whole unit out to get redone professionally or just buying a used motor to put in the car and just sell it or even selling it as is, or a renegade swap.

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If it's already in the air, pull the oil pan off. From everything I've read that should give you a good view of the state of things. Even better if you have a scope to stick up in there so you can look at the cylinders. Some pictures of such an investigation would probably garner some useful information for you to help figure out where you go next.

GT3 long block w/harness and ecu on sale now on eBay as another option. Coincidentally, someone else is selling a gt3 transmission too but I'm not sure how much in love you're with the car. If it was a forever car, it might be a good option. Just throwing that out there as you could have a low mileage bulletproof Mezger engine with 381hp for about the same price as a professional rebuild, and that's assuming your core is even good for a rebuild candidate.

That sounds incredibly bad ***. This car would be amazing with 381 hp and GT3 gear box. I am something along those lines or just shipping the whole thing off to Jake for it to just be DONE and garunteed and done correctly Trying myself which could work, huge undertaking or just slapping a GM V8 into it and beating the snot out of the car. I'll post up pictures as soon as I get the pan off

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I don't know of anyone in the US that has done a GT3 transplant. There are quite a few with JR's motor and LS swaps though... You'd def be one of a kind and would actually increase a 996 value, lol. Not to mention the GT3 Mezger engines were made for tracking without fears. I believe tracking JR's motors apart from special race motors voids the warranty IIRC.

I absolutely adore my 996 GT3 (after having several Carreras and Turbos), but I�m not sure you want to drop that engine/trans in a C2. One, you�d have to modify the firewall if I remember correctly, but more so, I think you�d run into quite a few issues with wiring, not to mention end up with a car that still has C2 brakes and suspension. I�d either rebuild that engine, or buy another used engine to put in it.

http://www.ebay.com/itm/99-02-Porsch...dWNCxH&vxp=mtr any one here ever bought an engine from these guys? I am between either this or a renegade swap at this point. Signed Steve

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This guy has...... https://rennlist.com/forums/996-foru...re-thread.html

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That's MB Motorsports and they're a sponsor here. You may want to contact them directly through the forums. I believe Zookie was one of his earliest customers that actually is a member here on the forum. You may want to contact him for any feedback and to see how his motor is still holding up.

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I hadn't connected that DrMEMs had one of Martin's motors, just that Martin was being Martin. The eBay ad says it has a 6 month warranty, but here is a quote from Martin in that thread (emphasis mine)... So is there a warranty or not?

I believe he warrants his rebuilt engines. The quote you supplied indicates used engines - and you'd be insane to offer a guarantee that someone else's used engines will be good for anything except displacing a fair amount of water.

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Here is the connection. https://rennlist.com/forums/996-foru...mentation.html

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Yeah that would make sense. It wasn't clear in the context of his ranting about the weakness of the M96 though. Yeah I re-read the thread after you posted the link. I meant I hadn't made the connection when the thread started.

Same response as Schell, he beat me to it.

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Dude, how many times do I have to tell you to leave the more complicated stuff for the more intelligent and just stick to making sure your 2x4's are straight. Intermittent misfire has nothing to do with the way I rebuild my engines. Most of my customers are not forum members. I rebuild 6-8 engines a month between my 2 locations here and in Poland. We have all kinds of customers ranging from business owners, lawyers, shops, authorized Porsche dealerships. If anyone wants to see how much work we have just visit our Facebook page, all details are there. Just an example: today we are in the process of rebuilding 3 engines: 3.2l, 3.4l and 3.8l. We have also sold 2 used motors today one 3.4l and one 3.6l. Those are the facts! I've attached pics below from my 3 rebuilds in Poland, from the top it's 3.8l, then 3.4l and 3.2l. My crew just sent me their daily report and pictures of what they've done today. My prices are the best on the market right now with the quality of work MB Motorsports has to offer. No other shop in US can beat that. It's because I have all best quality machine shops in Poland where I have moved all of my rebuilds. Europe is well known for high quality and reasonable prices where in US everyone wants to make the most money for low quality of work and products. It's mainly because of high maintenance costs of expenses, shop, taxes, building prices, etc... In the end every other shop and their services end up being crazy expensive and the quality is not always the best. Well maybe except for one guy in Ga who's quality is superior but his prices are crazy

Martin: You're just being funny by telling a forum member to "leave the complicated stuff to the more intelligent and just stick to making sure your 2x4's are straight", right?

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No, I'm not, he's a contractor (at least that's what he claims) so he should stick to what he knows best instead of trying to advise other members how to rebuild engines or about quality of my work he knows nothing about. Him and I have a history on this forum, he is always the first one to step in to pick on me publicly.

heres what looks like a nice 59K engine with IMS done 17K miles ago for $10K - long time member too: https://rennlist.com/forums/parts-ma...seats-etc.html

Ok. I understand "history". Some people will never see eye-to-eye with other's opinions or products. That's why there are so many choices. While I have never been a small business owner I do understand "pride in product". I also understand presenting oneself in a professional manner in "public". Every cross word and put down can reflect negatively on one's business and product. There are numerous folks on these forums who someday may need the service of a business like yours. They may make the decision based on how you present yourself. Food for thought.

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FIFY Dude.......your wife did a great job in writing that post....but you need to learn the minute you get respect here is when you give respect to your customers. You are also apples to oranges comparing yourself to FSI.

I have a 3.6 liter out of a 996 for sale. 3.6 conversion would give more power although it's not as straight forward as just swapping in another 3.4 liter. This motor does have L&N IMS, deep pan extension, and X51 baffle. So as it's priced it is very reasonable. Currently still in wrecked car so it could be heard running. Located in Houston Texas. Could be shipped. https://rennlist.com/forums/parts-ma...seats-etc.html Feel free to PM if interested or any questions.

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Don't expect me to be nice to people who are first to pick on me in public. My "competitors" had nothing but their stupid comments to say about me from the start or trying to outsmart me with their theories. This is why I act the way I do, once you start picking on me you start a war. I never get into anybody's business. I have a lot of customers who are very happy with our service once they meet us and know what we offer. I just sold another engine today in addition to what I sold yesterday. My customers want a great product at a very good price, that's what matters to them. If anyone here will have a blown motor sometime in the future they might or might not buy one of my motors, it will be their choice. If one of the guys who pick on me would ever want to buy my motor I wouldn't sell it even for 50k. Sneaky Pete used to pick on Jake back in the day, when his engine broke Jake wanted to kick his *** out in the first place. After he thought about it he took his business since he wanted to make money and SP wanted his engine fixed. I would kick him out the door, but that's just me.

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Yes, my wife wrote this post, she writes all of them. My English may not be perfect but it's enough to communicate. I also speak a little bit of German and Russian, and perfect Polish of course. That makes 4 languages that I can understand and somewhat speak. I bet you cannot say good morning in any other language than English. I came to this country and I run a successful business. I sell my motors all over the world. I wonder what would happen to you if you would start a new life in another country and not know anyone there or speak the language? I bet you couldn't even push a wheelbarrow at construction site.

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Yup I'll admit I was one of Jake's detractors and yes I went to him with my tail between my legs because he IS the guy when it comes to Porsche motors. The rest of your comment is inaccurate. My 996 motor broke during a track day. I found a donor motor at FSI. Yes Jake did not have to sell me the motor....when we spoke I told him who I was and we had a candid conversation and developed a friendship. The motor came without a warranty. Fast forward to 9000 miles later the motor develops intermix. I remove the motor and send it to him and Jake repaired it on his dime and sends it back. I re-install it. The car still ran sour so Jake sends a truck and trailer and took my car to Georgia. He fixed it and sent the car back to me....all at his expense. That whole process of performance and customer service won me over. The current 4.0 that he built me is a monster. Martin, you are NOT the guy.

Any chance you guys could conduct your ongoing pecker contest via PM or email?

Could it be this? I did a friends IMS bearing yesterday, 43,000 mile car. While reinstalling the chain tensioner, I noticed that it wouldn't insert more than half way back into the engine. pulled it out, picked up flash light and took a look inside the hole. Found this wedged inside. This was a total WTF moment Used needle nose to remove. Will This will req a complete teardown, if I am looking at the exploded pic correctly its yes and he cant run without it.

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This same photo was submitted via email to us yesterday (I relied last night). While mode of failure #7 (crankshaft end thrust shim failure) could have a similar result as the failure in this thread, the symptoms are much different. Its easy to find #7, just grab the crank pulley and push it fore and aft, and that tells the tale every time.

FLAT 6. that must have been Jeff that beat me to the question Thanks for your reply.

Quite amazing the engine still ran with a missing thrust bearing. It's good that you caught it. Btw, what happened to the OP?

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No, we see this one quite often.. If it runs long enough it'll break a timing chain or rod bolts from the crank banging fore and aft.

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Without realizing it you are generalizing and throwing out negative comments to many here on the board. You're condescending and insulting at the same time. I can't see how anyone on this board would seek out your services. Just FYI, nearly all US children are required to learn a second language in grade school and/or high school. While I've forgotten most it, I learned Spanish in high school. Our two kids speak fairly good French (as evidenced by our trip to Europe last year) as well as Mandarin Chinese. I only mention this because you're so quick to point out how eastern Europeans are superior to Americans in so many ways. I'd be willing to bet we're alike in more ways than you'd care to admit. Unfortunately you can't see past this pissing contest you've created with a contributor here. Would you please calm the F down or leave.