Maybe PorscheDoc or someone else knows if this is normal or not, but today I was doing some cat and mouse with a 997 on the highway. I had the revs up to around 6500 rpm, then upshifted, and when I looked in the rearview a huge puff of dark grey smoke bellowed from the rear and completely engulfed the car behind me (hehe). I stopped to check the oil right after and the meter still showed full. Haven't noticed any leaking at all. Note that I had spun out a couple of days before which made the engine konk out, and this was the first time I had the revs that high since then. I've got a 2001 C2.

What do you guys think?

 

A dark puff of smoke is somewhat normal on a hard upshift, keep your eye on it and make sure it doesn't get any worse. Could possibly have a leaky injector or something.

 

I'll keep an eye on it. Haven't seen it again and I did a hard drive this morning. Thanks PorscheDoc!

 

PorscheDoc (et. al.), so I did a mountain run today, and I saw this happen twice. Same scenario where I upshifted at around 6500 rpm. Note that I had the o-rings and cam cover seals replaced before I picked up the car 3 weeks ago. Could it be that the o-rings haven't properly set yet?

 

Ok, so I talked to the mechanic that worked on the car. He was saying that dark blue smoke like that is usually excess fuel burning off. From what I understand, he said that when you're going full throttle, there's a switch that opens up, and if you pull off the throttle rapidly (i.e. when upshifting) some fuel may leak before the switch closes,causing it to burn off when the throttle kicks in again. So ultimately he's saying it's fuel burning, not oil. He said oil is usually white in color, which makes sense since that's what I see when I start the car again after a hard drive. I have a lot to learn....

 

Exactly, it is normal on a hard upshift. You are dumping so much fuel into the cylinders, that when you let of the throttle, of course your spark slows down, allowing a little extra fuel in to the cylinder. On the next spark, it ignites all the extra fuel, producing the puff of smoke. If it is only doing it on the shift, then you are ok. If you are constantly blowing smoke, then you have an issue.

 

Thanks PorscheDoc!

 

AEM ....!Ahhemm...!Quiteordinaryona hard upshift. Your'egas into the cylinders, that when you the speed,and of course your spark slows down, . On the next spark, it ignites all the extra fuel, producing that blastof smoke.If it is only doing it on the shift, then you are ok. If you are constantly blowin smoke, then you have to go for a check up.

 

Oh.. Brother...,

Is it me, or am I hearing an echo in here.[X(]

 

Yea well, at least it re-confirms my car is ok.