Mechanics

BLACK SMOKE AND OIL ON PISTON

1995 Pontiac Grand Am

Engine Performance problem
1995 Pontiac Grand Am 4 cyl Two Wheel Drive Automatic 115000 miles

the question I have is if you would happen to know why black smoke is comming out my exahaust and the vehicle idles rough but when you go to move it it starts out really rough and you have to give a lot of gas to get anywhere misses real bad and I had removed spark plugs to check for oil on the back to see if that was the problem and there is oil on the back of spark plug 1 do you have any ideas or suggestions I was thinking piston rings but that is a costly process and want to have a better understanding of what is going on before I go through that kind of trouble thanks
Avatar
Ibmalor
January 5, 2009.




Hi there,

Black smoke is fuel fouling and if the plug is wet you may have a faulty plug, lead or leaking injector. You can do a wet comp test to prove the rings, that is do a normal test a and then add a small amount of engine oil to the cylinder, if the comp rises the rings are leaking if not it will be a valve problem, check this out first.

Mark (mhpautos)

Mhpautos
Jan 5, 2009.


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