blakebmxr3
NAXJA Forum User
- Location
- Robins AFB GA
I have an 89 xj with a 4.0 engine with 180,000 miles on it and there is a loud rattling noise that is constant at idle and acceleration, hot and cold. My oil pressure starts out(cold) at barely 36psi, then drops significantly as it warms up and eventually has next to no oil pressure at idle. My plans are to replace the rear main seal, oil pan gasket, oil pump/pickup, switch to 20-50 oil and an upgraded oil filter. I want to replace the main crank bearings and rod bearings, but I've been told that changing the bearings could ultimately destroy my engine. So im not sure what to do. Anyways, I've been doing a lot of reading on these forums about bearings and heard a lot about "plastiguage" and i dont know what it is. How do i determine what size/type of bearings to replace the old ones?