Caddy 4100 V8 oil problem

Friend of mine has an 87 Cadillac with the 4100 V8. Abruptly it starting using lots of oil. About two quarts per tank of gas, and the fuel mileage is
bad now too. What could cause that? Intake leak? BTW: It's not losing coolant.
Al
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Since it holds only 5qts this isn't good. Is it leaking or showing signs of being burnt via the exhaust? Leaking is a common problem with this engine....case mating problem....but another thing is the seals getting elderly. How many miles? Has the oil been changed, at least, according to the maintenance schedule?
If it's being burnt, then it could be a valve-train problem or ring problem. Do a compression check or, even better, an air-leak test.
Not losing coolant is very good.
Dave S(Texas)
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Thanks. This started very abruptly, so I don't think it's a ring problem. It's not leaking where you can see it on the garage floor. The car is smoking. My friend is in another state so I can't look at it. He said, it started smoking so he took it to a garage to have it looked at. They changed the alternator and battery. Don't laugh, it's true. Anyway the smoke continues....
Al
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snipped-for-privacy@webtv.net wrote:

You are thinking of the Northstar Cadillac engine. The older engines did not have a split crankcase.
Ian
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I would look at the air cleaner and PCV valve. If it can't get air then it will suck oil, at least I've seen it before. Other than that looks like either valve seals or piston rings.
wrote:

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I agree. In cold areas, the oil breather system will ice up if the car is only driven for short runs.

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