1991 Chevy Silverado oil useage

1991 CHEVROLET SILVERADO
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LUCKYJIMMY1951
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Engine Mechanical problem
1991 Chevy Silverado V8 Four Wheel Drive Automatic 125k miles
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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.
Apr 4, 2008 at 4:08 PM
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MHPAUTOS
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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 4, 2008 at 5:28 PM
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RASMATAZ
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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


https://images.2carpros.com/forum/automotive_pictures/12900_vac5_1.gif

HTH plus the earlier suggestion by Mark
Apr 5, 2008 at 12:05 AM
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