Engine Performance problem
1988 GMC Van V8 Two Wheel Drive Automatic 87000 miles
I just purchased the van and drove it 500 miles. It used about 2 quarts of oil on the trip and the fuel economy was terrible.
Twice while driving along @ 65-70 mph without accelerating there was a huge puff of black smoke that came out. The tailpipe has heavy carbon buildup but when the engine is first started and as it is driven there is no evidence of smoking. The engine sounds very good and tight and there's no clacking of valves or knocking sounds. There are no oil leaks to be found.
My question is; is the oil going out the exhaust and why. What could be the cause. And could I have damaged the cat or 02 sensors.
Thursday, April 9th, 2009 AT 7:18 PM