RENIXBEAST

89 xj 4.0 auto. I have an oil leak from the rear main seal and it leaks a fair amount. The problem is my oil always reads full??? I have been checking my radiator coolant and I loose maybe a cup every 2-3 weeks. My dipstick occasionally shows white sludge and sometimes tiny bubbles. It doesn't overheat or run hot at all, it actually runs a little cool like 180-200 on hot day.. I was wondering if it is a sign that my head gasket needs replaced. My engine has 240,000 is it worth a head gasket??

redrunner

Compress test both the engine and cooling system. Do you get any white smoke? That is a sign of burnt coolant. The white foamies in the oil is a sign of water getting into the oil some way. Head gasket or a crack some place.
Compression testing the motor would or should show a low cylinder that could be leaking coolant into a chamber. When you pull the plugs see if any show signs of moisture on the plugs themselves. What about any bubbles in the cooling system. A radiator shop can test the water to see if it has any compression gases getting into the water. It is a simple dip test. Does take very long or cost much. I have done the head on my and it is not that bad of a job.

Hope this helps.

RENIXBEAST

No smoke at all. I will try a compression test. thanks

JeepingDan

have you crawed underneath and looked for green? Theres a freeze out plug behind the flexplate that rots out

RENIXBEAST

No green underneath. Its weird cuz the oil leak isn't constant. I replaced the oil pan gasket and had no leaks at all, then all of a sudden oil will leak from every seal. One day it leaks the next day it doesn't. One day my oil pressure will be 40 at idle the next 10-20. Its weird