I have an old Willys with a 1976 Buick V6 231 cu. in engine. Don't ask how many miles (no speedo) but it runs fine and is quiet. I had a gauge that sends oil from a fitting on the block to the gauge. It read 40 psi at start up when engine was cold. After it got hot, it would read 10 psi at 3000 rpm and 0 to 5 psi at idle speed. I wasn't confident the gauge worked properly as the engine was quiet and ran great. I replaced the gauge with one that had an electronic sending unit. I still get 40 psi on start up,but after warm up I get 25 psi at 3000 rpm and it's still 0 to 5 psi at idle speed. I've rebuilt the oil pump (clearances are spec. and I primed the pump with petroleum jelly as per instructions), I've replaced the oil pick-up tube and screen and even tried 15W-40 instead of 10W-30. No change in oil pressure. When I pulled the pan there was no evidence of sludge. Can the oil pressure really be that low with no noise? Are my bearings worn out? How about an internal oil leak?

Gerry