My base 3.6 997.2 smokes heavily under hard acceleration. Under normal driving it is fine but if I nail the pedal and the rpms rise a huge plume of smoke is spewed by my exhaust. This cannot possibly be normal. My 07' did not do this. Can anyone else let me know if this is happening to them? Any ideas what this could be?

 

black or white smoke?

 

I've never had that problem. Thats not normal.

 

When I was trying out my 997.2, one of the cars I tried released a nice cloud of gray smoke. I ask the salesperson about it and HE said that the DFI car burns some oil at cold start or hard acceleration in order to improve lubrication. My car does that from time to time as well... Make no mistake, it is drinking a lot of oil, about a quarter every 750 miles but also according to the stelearship, it's "normal".

Still sounds odd to me, as I recall, old motorcycle engines do that...

 

Is it smoke or just soot? The DFI cars produce a lot of soot and when you hit it hard it blows soot out of the pipes. Can be quite spectacular at speed. One of my friends in a car behind me said it looked like I lit the "afterburners" when I took off.

 

My car does this too, when I push the car hard and park it, usually the next time I start it up I get a cloud of white/greyish smoke... I had a thread on this b4 , I took it to the dealer and they blamed it on some BS, got $260 out of me, and sent me home...a week later and it still did it, Until a few memembers told me more about the smoke

 

If it is white smoke on start up make sure you run the car easy or a a mile or so before you shut it off. I've seen the white smoke issue at the track but never experianced it myself.

If it is a puff of black smoke under hard accelleration then that is the soot being blown out of the exhaust. Black smoke all the time can be a rich running issue too. White/blue smoke all the time is oil burning issue.

 

So can someone explain if this soot issue is from running rich/incomplete combustion (i.e. wasting gas) or is it a result of blowby oil being burnt in the combustion process?

I have been told that in other "performance vehicles" the catalytic converters can become "sooted up" if the vehicle is not being periodically " blown out". A remedy was to rev the engine to about 4000 rpm for 60 seconds to heat up the cats and burn off any residue. Probably an urban legend, but who really knows the source of this soot.

 

"Smokes heavily under acceleration" is not a puff of white smoke on start up. Boxer engines will leak a little oil into the cylinder heads at rest and cause some white smoke on start up. It's not a DFI issue. There is some increased sooting of the tailpipes reported w/ DFI. However, what you are describing sounds more like a diesel engine under hard load which is not normal for a DFI gas engine. In 5500 miles and one year of use I've never noticed what you are reporting. You should consider taking the car to the dealer and have them check the engine for proper fuel/air mixture, timing, etc.

 

I've had my 09 C2S for over a year and no smoke, no oil consumption. If my car smoked heavily under throttle, I'd be at the dealership having it fixed.

 

The smoke is definitely white. I have taken it to the dealer and they drove it and said it was operating normally. My tail pipes are full of black soot though. I will take it to the dealer and let them have a look one more time. It's under warranty so it won't cost me anything.

 

White smoke doesn't sound like oil, but water... probably accumulated over time from not fully heating the engine/exhaust system due to short trips, then it burns off when you put some load on the system.

 

that's right! It so happens I work only 1 mile from the office so my engine really never fully warms up. Only on weekends when I can take longer trips and really accelerate does it do this. Mystery solved?