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Discussion Starter · #1 ·
I've got a 1989 SBC that was a rebuild that had about 5000 miles on it when I got it. It runs great but uses oil and fouls the number 8 plug but does not smoke. The plug fouls after several hundred miles, all the other plugs are good. I just replaced the valve stem seals on number 8 but I doubt that was the problem. It uses half a quart in about 300 miles. The oil pressure is 30 lbs at idle and 60 lbs at rpm.

It doesn't smoke when cold or when under a load or when you let off at high rpm. How it could use so much oil without smoking? There are no oil leaks and the crank case pressure is good, pcv valve is dry.

Is it possible that the intake is leaking on one cylinder, it's got an aluminum intake and I've heard some gaskets are too hard and don't seal well on aluminum.
 

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I've got a 1989 SBC that was a rebuild that had about 5000 miles on it when I got it. It runs great but uses oil and fouls the number 8 plug but does not smoke. The plug fouls after several hundred miles, all the other plugs are good. I just replaced the valve stem seals on number 8 but I doubt that was the problem. It uses half a quart in about 300 miles. The oil pressure is 30 lbs at idle and 60 lbs at rpm.

It doesn't smoke when cold or when under a load or when you let off at high rpm. How it could use so much oil without smoking? There are no oil leaks and the crank case pressure is good, pcv valve is dry.

Is it possible that the intake is leaking on one cylinder, it's got an aluminum intake and I've heard some gaskets are too hard and don't seal well on aluminum.
It could be a leak from the intake into number 8 but before pulling the intake off remove the rocker cover on number eight's side roll the engine over and observe the rocker movement to see if a cam lobe is wiped out.

Also, a vacuum check before diving in, a leak into the manifold should show a low but steady needle on idle that corrects as the RPMs come up. A wiped lobe will show a normal needle that dips everytime that cylinder comes around and stays that way as the RPMs are moderately raised.

Bogie
 

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Discussion Starter · #5 ·
I use print-O-seal gaskets for alum intakes. seem to work fine.

first thing in the morning with the engine cold. get someone to hold a white sheet of paper behind the exhuast and start the car and rev it up a few times.

Let it dry there should be water. then look to see if there is any oil on the paper. If so its burning oil for sure. Also check for black dust on the back of the car and bumper around the exhuast. check both pipe if you have dauls so you can compare.

A good running engine will burn a lot of oil without showing many signs. Its usally the old engine that shows the oil burning with thick white smoke.

I would do a leak down and compression test before taking anything apart. no reason to pull the intake and replace the gasket if you have a broken ring land. A broken oil ring land will still run ok in a v8 but will burn oil like mad.


Hope this helps
What will cause a good running engine to burn lots of oil?
 

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the head gaskets are standard, the intake gaskets from fel pro will had just a small bleed hole in the rear water jacket crossover, but a standard one will work. the valve covers are different and not interchangeable
 

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Discussion Starter · #8 ·
The intake gaskets were leaking oil on all cylinders, replaced the Felpro with some soft gaskets. Oil consumption problem solved and it runs much better.
 
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