smoke at start up

Over the weekend my 996 c4 developed a bit of a problem. All runs fine but when you start it up it fills most of the village with blueish white smoke. It spits out a huge plume and then it goes after a while. It all runs fine but there must me something quite serious? Any ideas?

Not unusual for 911s to smoke on start up. Its usually intermittant and generally nothing to worry about Both my 993 and 996tt did it to greater or lesser degress

I concur - not usual, but not unusual, if you see what I mean. Has happened on my 2001 C4 a handful of times in a year, normally after a long run after which the car has sat idle overnight of for a day or 2. Oil seepage in a flat engine into the combusiton chamber. Looks a lot worse than it actually is. Keep an eye on oil level, as you would normally, just to be sure that nothing more untoward is a possibility. Stephen

Hi - Could be a component on the breather system - theres a diaphragm that can puncture which leads to condensed crankcase gases (oil) entering the induction system when it shouldn't which ultimately can give these symptoms. Grant

its normal. on my c4s it does it and i have only done 15k in it

The wife's '99 Cabrio does it occasionally......scared me shi*less the first time! There doesn't seem to be any 'logic' behind when it happens either. Its done it after being stood for only a day.....we've just come back from a 3 week hol, it started first time, not a trace of smoke....go figure! :? Pete

A little bit of smoke is common and not of concern but the original post suggests a James Bond style smoke screen which is excessive.

I agree. Sounds like the Air/Oil Separator. Try taking off the inlet hose to the throttle body and taking a look inside. If you see an oily residue, that's usually the sign the AOS has split internally as Grant has mentioned.

I had the same with my 996C4S but really noticed a difference if I left it to cool at idle for a few minutes and then shut down...no smoke. Is yours garaged? I think the smoke is a combination oil (somehow) for the blue and condensation froma hard run (white). Like I say reduced/removed if a cooling period introduced.

mine too if its sits for a while without being driven. bit embarrasing if you have a mate round who wants to see the car and go out for a run..only for you to fill up the garage with smoke when you start it up. "thats normal" isnt a convincing response

I've never routinely noticed my 63,000m C4S blow excessive light blue smoke on start-up, hot or cold. Very occasionally while warmed up, a start-up produces small amounts of light blue smoke. From cold, I do see a small amount of dark blue/black smoke which clears quickly in the fast idle phase. I'm just guessing at that being mixture enrichment for the cold start-up. (Or, terminology for us more senior forum members - "choke") I don't know about others on here, but I always seem to conciously check for smoke on start-up! And, I always allow some engine idling before switching off.

Sometimes reading threads like this is the kiss of death. I drove my C2 Cab up to a regional office in Brum yesterday. 75 mile run door to door. Was there about 5 hours and sure enough, for the first time I got blue/grey smoke when starting up to head home. The consensus seems to be that it's nothing sinister unless in sufficient quantity to employ a chimney sweep. Just doesn't look right though, if you were viewing a car to buy and it spat smoke out you'd walk away.

my tt did it, my current gt3 does it. I find a throttle blip before shut off lessens it. It is random tho'. A characteristic of a flat 6.

My 02 Targa (65k) does it after a spirited drive - ahem. Shat myself when it first happened! I also sometimes get a smoke screen Mr Bond would be proud of after a particularly satisfying fast left hander. I removed the throttle body to check for oil as per the separator issue, and it was as dry as a bone.

I would be inclined to look at the AOS, air oil separator. This is certainly the most likely and not to expensive to fix. I had an explanation at the Porsche Experience Centre on 24/06/09 for start up smoke. If the ring gaps end up at the lowest point ie at the bottom on the Porsche boxer cylinder configuration this can (and will) cause start up smoke. (Piston rings do revolve a bit a bit arround the piston, but this is more likely on a Porsche because of the boxer configuration. Regards Big Bob :bye: