Okay, my Dad has been concerned lately about the oil pressure in his '95 K2500 7.4 Sub.
When you first fire it up, you get between 70-80 psi (which I would expect), but when it gets to operating temperature (200-210), the oil pressure drops down to about 20 psi.
The previous owner had this same issue, and prior to selling the truck to my Dad, had a high volume pump installed. Pressure is the same as it was prior to the pump.
About a month and a half ago, we were heading to LA, and when we got into the hills (Acton), Dad decided to put his foot in it and see what the boat anchor 7.4 could do. At RPM (4500 or so), it built enough pressure to blow out the rear main...No, we have not replaced the rear main yet, but we did use a bottle of bars stop leak, and to my surprise, it seems to have worked...
Now, 20 psi hot doesn't concern me, but it definitely concerns my Dad. This engine has almost 200K. I recently changed the oil, and smelled no fuel in it, so I know it isn't the rings. This truck does not smoke, even on start up, so I know it isn't guides, and there is absolutely no valve train noise, or lower end knock.
Does anybody think he needs to be concerned with the 20 psi? If so, any suggestions on remedies?
Is this 20 psi at idle Jess? Does it go up with the RPMs? 20 PSI at idle is acceptable. Many in the GM fraternity (Zora Duntov, Smokey Yunick, Warren Johnson) say all you need is 10 PSI per 1,000 RPMs.
This is an older thread, you may not receive a response, and could
be reviving an old thread. Please consider creating a new thread.
GM Truck Club Forum
A forum community dedicated to all General Motors truck owners and enthusiasts. Come join the discussion about performance, lift kits, wheels, tires, modifications, troubleshooting, maintenance, and more!