smoke on start up 996 3.6

[James44]

Had mine 3.5 years and it always has a good puff of while smoke on start up. Gets used only about twice a week and covered 12k miles in that time, car runs perfect, so I suspect it's 'normal'

[SteveTTT]

Bossitt said:

The car is parked in the garage every night, level, I can start the car 20 times and it does not smoke. Then yesterday I cleaned the car, took it out for a run " reasonably hard" and let the the engine cool on tick over. Car stood level for 20 min or so, started car to back into garage and PUFF. For about 20 secs, from each exhaust, again it smells like unburnt fuel. I can only explain it as, like when old cars exhaust smells when started with choke full on.

Used the car today, smoked on early morning start been ok since warmed up.

Also do you think I should worry about the damp RMS?

Thanks

I know this is an old thread, but I’d be interested to know what the outcome was on this. I have the exact same symptoms on my 2002 4S(93k miles with a recent boroscope inspection showing no issues). The car does get used for short runs however. Thanks, Steve

[cd1957]

Hi despite all the scare mongering on this site,I would say White smoke is condensation.The exhaust holds lots of water vapour, which expands drastically when you start the car.

The smoke could linger a while, if it is just condensation, where as borescore smoke is Blue and will be mostly left exahust and will go after a few seconds.

Chris

[Helicopter123]

anonymous said:

[redacted]

If it's blue, I would agree.

[AlasdairB10]

My 80k mile C2 (previously reviewed by Mr Cmoose himself) does it after sitting when driven hard or after it's been sitting for a while without a drive. Nothing to worry about - all part of the fun of a flat 6 engine (so long as its not excessive).

Also, if you aren't smoking after a long left hander you probably aren't driving it fast enough or you have a sump baffle.

My 996 has fsh (recently from Porsche), a new AOS and RMS etc all done.

My 997 GT3 also does it after its been sitting (albeit different engine).

[Noblebenn]

Mine was doing it and it is the Air Oil Separator that is at fault.

One way of diagnosing is by taking the oil filler cap off with the engine running. If there is noticeable suction on the cap and the smoke levels increase, then the AOS is the likely culprit.

[Rich G Rk54]

outdoormax said:

Thanks for your messages guys, I think I will drop it round to the local Porsche specialist just for piece of mind!
all the best Max

I too get a plume of blue smoke on my 996 C4s for 10 seconds on its first start up.. if I start the car again after 9 hours or so no smoke at all.. I’m going to get it checked incase of bore scoring.. it’s more of unburnt petrol smell than oil.. I might be wrong.. apparently it’s common .. 94k miles 2004