FTS

I do not think there is a definitive conclusion to the issue yet; however, everyone who has experienced the white smoke, including myself, seems to have seen it after hard runs, with oil temps closer to 260-275 range and with oil level above the max levels.

The issue does not seem to cause any negative effects, and cooling the engine for few mins after the hard run by keeping car running for 2-3 mins. seems to avoid the issue. The potential concerning issue though is that the famous 996 RMS oil leaks were first starting in this manner as well depending on the severity of the leak.

So at the end, I think everyone is somewhat on a wait and see mode; this does not mean that we are taking the cars easy, I'd rather have an issue surface up, if it ever will, while under warranty

CosmosC4S

I'm actually relieved after reading this thread. At least I'm not alone, and it's not a serious problem like I fried the engine or something like that!

I still have to watch and see how the car is like tomorrow.

So...I'm honored to be a member of the "White Smoke Club"

bet

The RMS leak (or intermediate shaft leaks which is commonly referred to as an RMS leak) is not related to smoke coming from the exhaust of the engine. Additionally, smoke is not a precursor to a RMS leak.

FTS

I heard differently, but not owning a 911, I'll take your word

Ernie J

Please read my last post on this issue. The oil separator is too small to handle to job. Oil is dumped into the intake manifold and is burned in the combustion chamber. You do lose HP when this happens and oil, it takes sometime before the engine is back to full power. The engine not designed to burn oil. We at MantisSport have had this problem since Sebring Club Race. We have been designing a oil breather system. We ,tomorrow are testing again, a modified version. The first design has worked no big smoke, max revs, the exhasut pipes are a nice grey/brown, no more black. and more hp. The first design was dumping oil mist out of the vent. Oil film all over the rear bumper. New baffling of the last breather tank will solve this. Oil in the combustion chamber causes the timing to be retarded. Knock sensors doing their job. Our race Cayman flies now against the c2, c2 turbos. Right now it will be a system only for racing. You can drive around this problem, just keep the revs down below 7k.

rkeyser

I've owned 10 Porsches with flat six engines (water and air cooled) and every single one would blow a big cloud of smoke at startup on occasion. Smoking while driving, however, should not happen.

willr

well, since starting this thread I've changed my oil again but made sure it was filled to 1 bar below max. Haven't had the problem again, despite driving the car harder than before.

FTS

Ernie:

I have been folowing Mantis' work since the beginning just like most of us, I have to say that it is very respectable and waiting on your further development.

As far as new breather tank baffle, why would it be just for off-road use, why is only for racing? I actually do not have a problem keeping it below 7K rpm as it does not seem that there is anything above that any way, but I am sometimes slow in shifting and don't want to watch the tach continuously

Thank you for the information.

Ernie J

Toaster, Right now we have it configured for our car. The exhaust system is such we have alot of room for the breather system. Actually I was looking at revamping the systemm to fit stock caymans. This will done after Daytona race

FTS

Sounds good, thanks Ernie.

designman

I keep my oil dead even between min and max.

Larry Cable

had this problem last week at Laguna Seca, started up a friends Cayman S after it had been sitting for 30 mins after the last (hard) session, HUGE clouds of white smoke upon startup, had to leave it for quite some time before the smoke finally cleared, it at first appeared serious but the car recovered.

Drigo

@Larry Cable, your friend should consider replacing his AOS with the motorsport version. I used to have the same problem at Laguna and occasionally at TH. The membrane in the stock AOS breaks down and oil gets ingested through the intake. The Motorsports AOS isn't cheap ($1125 for the 987 part), but it resolves the issue.

Larry Cable

ka-ching, thanks for the info! much appreciated!

KINGSRULE

It depends on where the groves in the piston rings line up when the motor is turned off

With the right alignment the rings let a bit of oil thru, thus smoke at start up