EXHAUST PLUME

davidcross · May 10, 2009

just fired the car up and after second turn of the key the car burst into life but with the biggest plume iof smoke from the exhaust pipes. not seen this before. car has been started this morning already no problems. cud it have something to do with it not firing up first time round? i think sometimes im guilty of not holding key round long enough wating for it to start. dunno if this means it floods engine with fuel. bit odd thats all...cheers

tscaptain · May 10, 2009

How long did you run it for in the morning David? Colour of smoke? I've read somewhere that starting from cold, running a short while then shutting down and leaving it is a good way to get a blast of oil smoke the next time you start up. If you do a search on the forum I think there are a number of posts about smoke on start up.

davidcross · May 10, 2009

i run it for about 15 mins this morning to go and get petrol then its sat in the garage all day. the smoke was sort of blue in colour and just stank of petrol

garyw · May 10, 2009

Sounds like the usual 911 start up smoke...[

]
mine does it after a short runtime and left to stand...
Common feature from the engine

garyw

dereksharpuk · May 10, 2009

Chacteristic of a flat six (boxer) engine. Pistons are horizontal and the oil control rings have gaps in them allowing oil to seep past as the engine cools. The 'plume' is quite normal, will vary in intensity, but should not last for more than a few seconds.

adrian996 · May 10, 2009

I'm no expert but if the car failed to start the first time then (assuming that the engine turned over at least once) all six cylinders would have been primed with petrol which would not have been burnt (because your engine failed to start for whatever reason). This fuel may then have mixed with the slight residue of engine oil that would have accumulated on the cylinder walls after you last switched the car off. This would have all then burnt together and created the blue coloured, slightly oily-smelling smoke that came out of the exhausts when it fired.

My car is left standing for long periods without being used and this is something that I've just got used to when I first start it up. I know that I'm a bit old-school but I think it's good to see an engine using a little bit of oil. I think that your car will have at least 2 or 3 piston rings per cylinder, plus the scraper ring and it's inevitable that some oil will occasionally find it's way into the combustion chamber - particularly when she's cold (which yours was) because the rings are cold and contracted and in this state are more likely to allow some oil through to the combustion chamber.

I would say you've got nothing to be concerned about.

Hope this helps.

Adrian.

davidcross · May 11, 2009

Really helpfull guys much appreciated. I suspected I had worried for no real reason but best to check I thought. The starting issue I don't really think is a problem, just something i've not done right I suspect. Must b getting old!! Cheers

happylarry · May 11, 2009

Sounds like the usual 911 start up smoke...[]
mine does it after a short runtime and left to stand...
Common feature from the engine

As above - mine does exactly this on nearly all trackdays - it's often so bad that the marshalls at the pit exit inform me that my engine is about to let go. So, I'm not too concerned - BUT will post if it ever does let go!!

Sandy59 · May 11, 2009

Mine does this occasionally and looks pretty bad for a few seconds then clears up. Of course it's virtually guaranteed to do this when there's any kind of audience which can be pretty embarrassing !!

evansash · May 12, 2009

Never had it on the 997 but facelifted 996 often on start up and occasionally whilst driving, as another member mentionned. I was not happy with what Porsche said and got rid of the car as I was afraid that it would let go and Porsche would do their usual wriggle to get out of warranty claim!