1991 Chevrolet Silverado

Engine Mechanical problem
1991 Chevy Silverado V8 Four Wheel Drive Automatic 125k miles

truck sat for 3 years runs real good no oil leaks compression is 195 all cyls. Smokes a little when it is started could this be a head problem or bad oil rings uses 1 qt. Of oil 100 miles does not smoke on the hiway where is the oil going.
April 4, 2008.

Hi there,

The smoke on start up is a good indication of worn vale stem seals and valve guides. Although you have good compression, the oil control rings may be suspect and a small but constant oil burning may not be visable, a good indication is when you back the throttle percentage off ant high way speed, this will give a very high engine vacuum reading and faulty rings ill show up with a puff of blue smoke then. You can try moving up a weight in the oil viscosity a well.
But oil consumption, if not an external leak, it's going out the exhaust.

Mark (mhpautos)

Apr 5, 2008.
Try this with a vacuum gauge hooked up to identify ring/s and oil control problem. Or use a compression gauge/leakdown tester

When throttle is opened and closed rapidly and needle falls to 0 and rises to only 24 or less inch

HTH plus the earlier suggestion by Mark

Apr 5, 2008.