Too rich is a very blue smoke. Oil is a dark blue/black/grey smoke.

 

im also having the same problem....i have black soot on my bumber around the exhaust pipe and looks like some oil spots....BUT, i do have a cat converter...so any ideas why? thanks

 

How old is the engine? If you are burning oil... that's probably why.

 

its a 98 gsr with a 99 engine...im using mobil 1 synthetic 10w30...how do i know if its burning oil? ive been checking my oil levels and it pretty much looks the same to me...doesnt look like any less than when i changed it

 

Rich = black smoke unless you are running a 2 cycle motor.

 

I've seen a fair number of rich running N/A RX-7's and various turbo cars, the gas fumes looked very blue to me.

 

Well RX7s' rotary motors burn oil when they run and the turbo cars could have bad seals in the turbo which would in turn be burnt off. Everythink i've ever read on the subject says black smoke = rich. Blue is oil burning. My car runs somewhat rich and there is some black soot above the exhaust tip. I also don't have a cat so i'm sure has something to do with it.

 

Not nearly enough to see, though. That's metered by a system independant of the fuel system, anyway.

 

What I was getting at with the RX7 thing was if the car was indeed running rich, it would have a black smoke mixed with the blue of the burning oil in the combustion chamber. That would be a very dark blue smoke. But hey I guess every car manual and internet site I've ever read on the subject is wrong, and you are right. I'm not going to pursue this converstation any longer as you obviously have your mind made up. I do, however, suggest you read up on the subject some and IF you find any evidence that states a car running rich will have a blue smoke then you post it here. That is all.

 

Won't cure a thing. We wish it were that simple.