Cayman goes KABOOM on track.... then dies

The day started out well enough. First track day of the year today at Mosport in clear, dry, but cool conditions. The CS was running great. The winter mods (Cross coilovers, H&R sways, lightweight flywheel and intake Plenum) have really transformed the car. During a fast afternoon session, between Turn 2 and Turn 3 (about 90 mph)the engine went KABOOM, and immediately cut out. Scared the sh*t out of me. Felt like someone kicked the back of my seat with 100 lb. boots just as I'm entering the braking zone for Turn 3. It was a violent bang (way beyond any kind of backfire) and I felt it through the steering wheel, the pedals and it even caused my rear view mirror to shift. I really thought I would see engine parts on the track behind me... Managed to coast to a stop a couple of turns later, but the car was dead with all idiot lights glowing. I tried to start the engine, but everytime I would turn the key, all it would do was go KABOOM again like soom kind of nuclear backfire, and die. After about 10 mins, I got the engine to re-start, but it was undrivable. Completely rough, backfiring/booming, heavy metallic (not good) clattering/banging and stalling. Once back in the pits it was 1-800- Porsche time. It's now been flatbedded to the dealership, and I'll find out tomorrow (hopefully) what the problems is. Did manage to call the dealership and talk to the Service Manager, and he suspects maybe a coil failure that caused unburned fuel to ignite (KABOOM) that caused a cam (or 2) to jump cogs - but he says he's never actually heard of that happening with a Cayman before. Not real comforting ... Clearly it's engine surgery of some degree (whatever the root cause turns out to be) and a warranty claim. Given that it happened on the track, and the car is significantly modified, I guess this will be a good test case for Porsche 's warranty position re modified and track abused cars. Can't hurt me that the track day was organized by a group (Apex) with a close affiliation with the Porsche dealership and their tuning shop. Sucks to have a good track day end with the CS on a flatbed. At least I know my Rennline tow hook works well. FYI, its an '06 CS with 33,001 kms and 38.75 track days. Curious (and sympathetic) if anyone else has experienced something similar ?

Sorry to hear this . . . Wow, sounds kind of serious - I guess it doesn't help to speculate until the service department makes a definite diagnosis, but did you see the thread by JackWood a few weeks back about his Cracked Coil ? Keep us posted on what happens.

bad cats maybe? I hope nothing too serious, keep us tuned in. Sounds too violent to be similar to Ken's pulley pin problem...

boinkus44- Sorry to hear about this. I will be watching for the outcome. Keep us up to speed. Good Luck! Dave

I don't think its a cat problem as I had that problem (twice) last year and the symptoms were very different, and much less severe - but I'd be very happy to be proven wrong. As for JackWoods's coil problem, I had read the thread previously, but didn't really make a connection until KS-CS mentioned it. Coincidence ? Hard to say. Hopefully I'll have a clear prognosis tomorrow. Keep you posted..

Personally I would have reverted to stock parts and then sent it to porsche . might be too much headache with all the mods. At least the dealer I go through are super anti-mod. good luck!

Would've been difficult to revert to stock parts since a good portion of my mods were done by dealership and/or their tuning shop - and the track day was essentially organized by the same group - so they saw first hand what went down.

This is the third engine failure in a CS I've heard about in as many days. It's so hard to figure why some engines go boom and others seem to last forever. I'll be eager to see what the diagnosis is. Good luck!

Well lets don't jump to conculsions about the Cayman engine. We do not yet know if it is an "engine failure" (hopefully not) and we do know that this is a modified car which suggests that this thread might be moved to the Modifications forum when we know the actual problem. Kudos to the OP for not trying to hide the modifications from Porsche . To do so would have violated a lot of folk's (like me) personal code of ethics. Like everyone else I'm hoping for good news.

What was your build date?

Just spoke with the service department at the dealership, and it looks like it will be at least a day before they can get to my CS. Given that this is long weekend in Canada, there's a chance it may be next Tuesday before they can get to it. Patience is not my strong suit .. As for the build date, I'm not really sure, but I'll try to find out. I purchased it in June '06 off the lot and it had been there for a couple of months, so I suspect it was a late '05 or early '06 build. Keep you posted

When I first read the title I was thinking this was going to be another oil ingestion thread, but man was I surprised. Sorry to hear about this, sounds fairly serious the way you described it. I can't believe they are making you wait that long just to find out what is wrong with it. I would go nuts. Good luck and I know you will keep us informed...

Hi Steve, I am glad they can look after your car in such a short period of time, given that the dealership is extemely busy. Keep us posted because I started worrying about the white puffs coming out of turn 10. Good luck. PS. I have a short clip of your car, pm me if you want it

webbie: just saw this picture on your site - do you know what happened?

That picture appeared last fall, as I recall. It was taken in Asia somewhere (Singapore??). There was a car show, and a lot of fast cars were running together on the freeway. Someone got frisky and crashed. At least that's what's in my foggy memory.

Really hate to hear this - hope it gets resolved quickly & you're back on the track soon. Good luck & definitely keep us posted.

It was taken in Malaysia, a whole convoy of Porsches were travelling north at high speed when a econobox moved to the fast lane and caused a cascade of braking, and this white one crashed into multiple armcos and caught fire.

This was talked about in this thread http://www.planet-9.com/cayman-chat/20651-burn-cayman-burn.html

Hmmmm..... What a mystery. What we know: This happened while braking into a turn A loud explosive bang followed by a stalled engine The engine restarted and was able to idle but it kept backfiring Metallic sound on restart At first I was thinking about a broken intermediate shaft, which could throw cams out of time and cause some nasty backfires into the intake manifold. But being able to restart the engine rules this out. A backfire into the exhaust wouldn't have shaken your car like that. A backfire into the intake manifold certainly could. And if it did backfire into the intake, it would probably blow off and/or destroy an intake hose. If that happened, it is conceivable that the engine could start and limp a little. Is there any chance you downshifted into the wrong gear? Based on the circumstances, it sort of sounds like you may have grabbed a wrong gear, over-revved the engine and smacked a valve with a piston. Because you have a light weight flywheel, this could happen very quickly without you even realizing you grabbed the wrong gear. If this happened, that smacked valve would stay open (because the stem would be bent). If it were an intake valve, that would cause some explosive backfires into the intake manifold. That would also cause the engine to stumble, skip, display a CEL and emit a very nasty metallic banging noise. I hope I'm wrong, because if I am not your engine is toast. Even if I am correct, I am pretty sure that Porsche would stand behind it and cover it under warranty, so don't panic yet. This will indeed be a very good test of the Porsche warranty. I suspect that Porsche will pleasantly surprise us all. Please keep us posted.

Why would porsche stand behind and cover an over-rev? that would seem the easiest type of claim to deny? they could point to the data and say "look there are X-amount of type-whatever over-revs. clear evidence of driver error & abuse...denied, here is your bill" I hope for the OP sakes that's not what happened but it seems a plausible explanation.

You are both right.:cheers: As a matter of official policy Porsche isn't going to pay for your mistakes. But...if a dealership can squeak through a warranty claim because THEY LIKE YOU...and a reasonable case can be made...it can happen. Let's hope our clubmate catches a lucky break. He isn't entitled to anything, of course, if it is the result of user error. But if a reasonable case can be made that this would have happened on the street, and the dealership is friendly...who knows?

ethics can be a tricky thing

That really sucks, I hope it doesnt get to replacing the engine! ________________________ "Sir! We're surrounded!" - "Excellent! We can shoot in any direction!" A good car will get you from point A to point B. A great car... will just get you into trouble!

Regarding Over-revs and engine damage, then what in the world is a rev limiter for? Or perhaps you increased your rev limiter with the Softronic software?

The rev limiter only protects you on acceleration - it doesn't protect against over-revs if you force a downshift to too low of a gear.

Great news ! I got a call this morning from the dealership (Pfaff Porsche ), and the CS is fixed and ready to go. The root cause - mass airflow sensor failure. I couldn't speak with the service tech, so I don't have the full story yet (i.e., how/why the sensor failed), but it seems that mass airflow sensor failed, causing the ECU to "shut down". Somehow this caused the KABOOM which blew the intake plenum (IPD) hose off. Still puzzled about the mechanical clattering that was evident when the car did start after the KABOOM. When I asked specifically about this, I was told that "that is what the motor sounds like with a failed mass airflow sensor and the intake plenum hose disconnected". They did note that the KABOOM may have seemed amplified because I have GT3 seats bolted directly to the floor. Picked up the CS a couple of hours ago, and it runs perfectly. 100% covered under warranty, no issues in that regard even with the mods and the heavy tracking. The only question they asked me is if I was going to the May 22 track day they are organizing at Mosport. Sounds like a good idea. Bottom line, even though the symptons of the sensor failure were severe, I've been assured there is "abolutely nothing wrong with the motor". And they did check for over revs, but there was no issue there. All in all, great service and I am kind of shocked (maybe a little embarassed) that something that appeared so severe, turned out be relatively minor. I am going to speak directly with the service tech on Tuesday, so I should have some more detail and insight to add to the story. In the meantime, anyone else experienced a mass airflow sensor failure ? If so, what were the symptoms ?

Glad it turned out well ________________________ "Sir! We're surrounded!" - "Excellent! We can shoot in any direction!" A good car will get you from point A to point B. A great car... will just get you into trouble!

That's a relief . . . sort of I'm glad it wasn't as serious as we initially thought it might be, however, I hope you can find out more (and enlighten us) about: 1. Why the MAF sensor failed in the first place and, 2. How that could cause an apparently very large detonation sufficient to blow your plenum hose off?

Gator Bite, Good info.Thanks. FYI my CS is desnorked and uses an EVOMS cold air intake. I've had that setup for two years without incident. The only change made this year on the intake side is the IPD plenum , and it was the first track day with the IPD plenum in the mix. As for the KABOOM, I think your theory is correct, the DME was fooled into dumping large amounts of fuel that ignited with a KABOOM - possibly from the heat of the headers ? All I know is that everything happened fast. KABOOM, and the engine dying. It's possible the engine kicked out momentarily before the KABOOM or vica versa, or simultaneously. Hard to tell. At the moment I was more concerned about making the corner. I'll try to get more info from Pfaff, but for now, I'm following your advice - driving the CS and enjoying it.

Happy to hear that all you needed was a minor repair. MAF sensors do go bad. But I never heard about a KABOOM before. Have fun at your next track day!

Very glad it turned out to be no biggie... Best possible outcome and sounds like you have a helpful, cool dealership.