Black Smoke - W202
 

I have a '94 C180 with 80K and a recent new head gasket and seal kit etc.
My brother was driving behind me yesterday and told me that every time I changed gear my exhaust blew out a puff of black smoke - I was driving nearly full throttle - Any body know what might be causing this and is it serious ?

Thks:)

black smoke
 

Generally black smoke is unburned fuel. Intermittent black smoke as you shift does indicate some problem, though perhaps minor, in engine tune or built up carbon coming loose. The fact that it only occurs when shifting is reason to have some relief. I'm sure other's more knowledgeable as myself will be able to address this more fully. It's possible that your initial timing is a bit retarded. Do you see the same puff of black smoke if you just accelerate engine speed with no load (stopped)?

Bad unjectors, or dirty. New plugs perhaps, as other
 

Posted said black smoke is usually fuel mixutre and blue is oil, could be a dirty TB also