Sorry to hear about your friend Mike. I just hooked up a pressure guage on mine. The pressure starts off at 32 PSI when first started. While waiting for the engine to warm up, I noticed the pressure slowly dropping. After about five minutes it had dropped to 26 PSI. Five minutes later it was at 20 PSI so on and so fourth until I got to 15 PSI. The book says to warm the engine and rev it to 2500 RPM and the guage should read 40 PSI. When I revved it to 2500, it only got to 30 PSI. I'm using 20w50 Castrol Dino Juice. I haven't noticed any metalic substances in the oil when I drain it, so I'm still at a loss right now (loss of pressure and ideas).

 

So, how many miles on the engine, have you ever done an engine flush??
Mike

 

I have 90,000 now and I have had it since 38,000. I haven't done it and I doubt it was done before me. I'm in the process of checking the main bearings now. The engine might be dirty, but I have probably done five oil changes in the last month chasing this problem down and it's been clean every time. I figured you were right with the mains. When the engine warms up, the pressure goes down which might mean as the metal gets hot and expands the tolerances get worse.

 

Tim,
If you haven't pulled the pan yet, consider doing a good engine flush first. Try draining your engine and adding 6 qts. of ATF, let it idle for 10 to 20 minutes, don't drive it.
Drain it and then pull your pan and do your inspection.
Mike