I have put a motor (2.4) that was in perfect running order 13 years ago into service again. It had great oil pressure when it was removed. I stored in a a shrinkwrap and turned it over by hand every couple of months.

I've noticed that the oil pressure when cold is great (70# @3K). After it gets hot it appears that the oil pressure only runs about 20# at 3K. I've also noticed that the oil pressure guage, every now and then, will jump up to 40# for a second and then back down again.

I've replaced the sending unit, but it still seems to do the same thing. I'm going to replace the oil thermostat next (because it's easy). I've also got 2 new pressure relief valves/pistons to replace.

The question I have is: where is the second pressure relief valve? I know about the one on the bottom of the case. Can I get to the second one without removing the motor?

Thanks for any advice you can give me. Rich Lorenz