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blowby

Need more info!!! 80 miles/qt seems extreme...
Does it have any leaks? Rear Main seals are known to leak on these quite often, and can cause an extreme amt of oil consumption....
Does the air filter often get oil soaked???? This is usually caused by excess crankcase pressure, which could be worn rings.... Could also be plugged PCV/ vacuum port, or chamber in the valve cover... There is a fix for this that at least keeps the oil from soaking the air filter....
 
I would clean up the PCV system. Those are known to get gunked up on the RENIX injection motors. My 88 PCV system was clogged bad. I cleaned it up and it ran like a champ.
 
I bought a 92 YJ for $500 because the prior owner said it had a bad head gasket. I replaced the PVC and thermostat and solved ALL the problems. It stopped overheating and didn't blow any more oil. Ran that engine for another three years (with my 16 year old driving it), took it to the Rubicon and everything. Always had some valvetrain noises, but not too bad.

(Now it's got a V8 :awesomework: )

PS. Do a compression test and a leak-down test. That'll help diagnose it
 
the only places it leaks is the valve cover gasket and the vent hose at the front of the valve cover that goes into the air box. it killed my k&n filter
 
If it's pumping out the front crankcase breather, you need to check the vacuum line at the back of the valve cover, disconnect it and see if there's vacuum at that line with it running...if not, you need to trace it to the intake and make sure there isn't a break in the line, or that the intake port isn't plugged. If you DO have vacuum at the line, then you need to pull the VC and check to see that the chamber isn't plugged up with sludge/carbon....
 
Clean the CCV and the air hose coming back to the valve cover (where the blowby gets pushed up) gets redirected to a can with 2 lines in/out. Change to synthetic oil (I run Napa 15W50 in mine)
 
zukkev said:
If it's pumping out the front crankcase breather, you need to check the vacuum line at the back of the valve cover, disconnect it and see if there's vacuum at that line with it running...if not, you need to trace it to the intake and make sure there isn't a break in the line, or that the intake port isn't plugged. If you DO have vacuum at the line, then you need to pull the VC and check to see that the chamber isn't plugged up with sludge/carbon....
Click to expand...

^this. I have an 89 that used to have the same problem. Removed the PVC line from the back of the valve cover and replaced it with a piece of 1/4 ID heater hose (had to hose clamp it down on the intake manifold). That solved like 80% of the blowby issues. I later ended up taking off the valve cover and cleaning out the sludge and that completely solved the problem.
 
yep. my 95 had same thing. you'll need a new rubber grommet if you take the breather out of the valve cover. i just replaced the whole bit with factory parts and it wasnt too bad.
 

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