Possible Engine Failure

Hello All, I had a very unfortunate situation happen this past Sunday, would love any input that could be provided. So quick background, I purchased this 2004 C4S in February. It had 73k miles, IMS solution done and had a good PPI and boroscope performed, everything checked out. I drove it from Orange county down to where I live in San Diego, got a fresh liquimolly oil change and oil analysis done and everything looked good there. Since then I've put about 800 miles on the car with zero issues. I always start it, drive right away, and don't go hard/shift past 3k until oil is at operating temp. This Sunday I was driving the car, engine was at temp and I went to shift from 2nd to 3rd about about 4k. Once I made the shift, I heard the worst sound you could imagine, like if the engine was dropped in a garbage disposal. All lights lit up, lost power, cruised to a safe spot, did try to turn over again but it failed. Any ideas as to what I could have experienced? I've had the fear of bore scoring since before I even took ownership, and feel that that would not happen as sudden as this occured. Also, as mentioned prior, IMS was taken care of. Please provide any input, hoping it's not full engine failure. If that is the case, if anyone can recommend what people do in that situation i.e. options for rebuild/standard price? Sell as a roller? etc. Thanks, Mike

Sit down and breath, then open your wallet. Get it diagnosed first by a reputable Porsche mechanic.

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Bore scoring wouldn't normally make that noise or the lock-up you wrote about. Don't try to start it again. Drop the pan and look for junk in the pan. I understand you say the car has The Solution, but the IMSB failure sound has been described as "Marbles rattling around in a tin can." Did it sound like that?

Could be many things. But what comes to mind first is a broken timing chain. I agree with Wildbilly32, drop the pan and take a look. Your options depend upon what you find.

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Didn't necessarily sound like marbles in a can. Timing chain was mechanics guess before going tearing it apart as well. What sort of damage would I be looking at if it is timing chain?

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If this is true and you didn't mistakenly call the IMS Retrofit the "solution" (not meaning to insult your intelligence - this mistake happens often on here,) then you wouldn't have any marbles to shake up your can, anyhow.

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You need a new engine if the timing chain let go.

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If it is that, is this something that a PPI should've caught?

Broken timing chain means the engine is not worth rebuilding. PPI won't find that normally. But usually a timing chain breaks at idle.

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Appreciate the information, and I'll just see what things look like once they can fully diag. If we are looking at absolute worst case scenario, meaning new engine etc. Should I be expecting a $30k bill, more/less?

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Were the cam deviation numbers checked/recorded during the PPI? Engine over revs? Oil filter removed and inspected? Oil sampling performed? How was the bore scoring inspection done (via spark plug holes or oil pan removed)?

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I I'm not sure on cam deviation numbers checked, but this is the PPI. The over revs were checked, the oil filter was checked, boroscope was done via the spark plug holes

You will not be able to tell more before dropping the sump and inspecting what�s in there. if it�s the timing chain, there is no way to find it during a standard PPI.

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Spark plug holes are not the best place to check for scoring as it starts on the skirt. Having said that bore scoring won't make the engine go boom like that. It sounds like timing chain, i might be wrong but i think it's been posted here 3.6 engines have more failure prone timing chains than 3.4 engines, someone else might comfirm

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Correct, all of above. From what I've been told, 2002 are the worst at breaking timing chains. But any 996 can break one.

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Any idea why 2002? What's different about the design?

Worth having Vollig Autoworks look at it. They�re a great place for Porsche work in San Diego

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Could be vendor quality control problems or swapping vendors. Porsche during the boxster/996 had other vendor problems like a bunch of bad blocks they tried to re-sleeve which went about as well as you'd expect. They were all pretty much swapped under warranty

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yeah I do like Vollig, the car is at Charlie�s Foreign auto. I like them too and they�re closer to where I live

I'll offer up my armchair opinion/hypothesis also.. I don't think it's bore scoring ......bore scoring doesn't go from 0-to-boom like that ... I don't think it's a failed rod or rod bolt.........rods and rod bolts don't fail at 4k rpm I don't think it's IMSB ...if you have the "Solution" they have a "soft fail"...not a "hard fail" like ball bearings can have...( marbles in a tin can).. I don't think it spun a rod bearing/oil starvation...........4k rpm isn't that high and you didn't say you had been in a long high-g turn That only leaves about two others, dropped a valve seat or popped a timing chain....if it was a 2002 I'd lean toward a dropped valve seat, but since it's an 2004 I'd lean toward a popped timing chain... What are the collateral damages from a popped timing chain? Well that depends on the RPM at the moment the timing chain pops... All m96's are "interference engines" meaning if the cam stops turning, the pistons "can" hit the valves.. .If the timing chain pops at a red light, there is a good chance the cam will stop rotating in a position that the pistons do not hit the valves, If the chain pops at 4k rpm most likely the pistons will hit the valves and further collateral damage will occur ( chain reaction), the extent of collateral damage/chain reaction can be as small as just bent exhaust valves, all the way up to broken valves, busted pistons, broken rods, busted crankcase/cylinders..ie. total destruction I remember back in 2010 when Porsche went to aluminum bolts for the vario-cam vane adjusters in the Panamera, Cayenne and Gt3...When I first saw them during P10 Training I said" uht oh, that looks like trouble"....But Porsche was very proud of the weight savings of the aluminum bolts and other updates of the vario-can...Then sure enough, the aluminum bolts started popping the heads off them...cams would stop turning just like if the timing chain broke...Porsche issued a "Service Action" ( ie. Recall) to replace all the early 2010 Panamera, Cayenne, Gt3 aluminum bolts to steel bolts, but not before many had failed.. If the engine was at a stop light when it failed, all we had to do was find all the bolt heads and install new steel bolts and re-time..all good..but if the engine was at high RPM when the aluminum bolts popped, it had to get a new engine due to all the collateral damage/chain reaction.. I'm hoping your engine suffered minimal collateral damage and can be saved..... BTW ; what usually starts this happening is a little roller shell from the timing chain breaks off and gets sucked up by the return oil pump ( scavenge pump) which locks the pump, this puts excess stress to where either the return pump breaks the drive, or the exhaust cam gear drive breaks or the timing chain breaks...since the timing chain now has a weak link, it is usually the first to break.,,then the further chain-reaction/collateral damage depends on the RPM's....

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Thank you for sharing this. Super informative and hopefully I should know within a day or two the extent of the damage.

Hopefully not a catastrophic failure, but there is life after the M96�.

These engines sound funny with a bad ignition coil too... A broken timing chain is easy to check for so hopefully you'll hear something back soon. If you were so inclined, you could pop out the scavenge pumps and start turning the engine over manually. If either of them don't move (or the engine doesn't want to rotate), you're going to have a bad day. Not a foregone conclusion at this point though, hope it's something more minor!