Your oil pressure should go up as the RPM's increase. How many miles do you have on this motor? Mine has 165xxx and it is starting to show signs of wear. I recently installed a high volume oil pump that got me a few more miles out of mine. Usually if the rod bearings are getting loose, you will hear a knock. When Main bearings get loose, sometimes you may not hear a knock. One sure fire hint of bad Main bearings, is - Under a load, when you increase the RPMs, the Oil Pressure Drops. Cam Bearings also could have alot to do with your oil pressure woes. Of course, I would check the motor with a good mechanical gauge. If your motor is dropping lower than 5 pounds, chances are you have some problems or will soon. My 400 carries 30 psi at idle in neutral, hot. When I pull it into gear, it goes down to 20 psi. I have Autometer gauges and a 15 psi sending unit on an Autometer Pro Light. You may try a couple of things after testing the pressure with a mechanical gauge. Switch to a semi synthetic oil. This helped my motor alot. You can also pull the pan and install a high volume pump. This will only provide more oil, not fix your bearing problem. Be sure to install a new rear main seal while you have the pan off, if yours is leaking. I also pulled the rear main cap off and inspected the bearing. Mine looked pretty good for the amount of miles. Good Luck.
<font color=red>Mudzer</font color=red>
1978/91 K5 Blazer
