ENG OIL PRESSURE

[CashpitC10]

Have 83c10 with a 305 just changed oil less than a month ago. When i stop at a red light or stop sign the oil pressure drops below 20lbs. What could be the cause of this? Any help would be great.    Thanks Jody

[bd]

Have you checked the oil level?  How many miles on the engine?  What's the oil pressure at 1,500+ RPM?  Was there a sudden decrease in oil pressure at idle or has it been this way for some time?  Have you verified the oil pressure using a manual test gauge or are you relying on the factory dash gauge?

[Shifty]

The olde small-block Chevy formula was 10 pounds per 1,000 rpm, if that means anything to ya.

[bedwards]

If your talking factory gauge, they are notoriously inaccurate.

[Shifty]

If your talking factory gauge, they are notoriously inaccurate.

Agreed.  According to mine, I should be pushing the truck instead of driving. 

[JohnnyPopper]

Are you using a multi viscousity oil, like 10-30?

Might be too light for a truck with high mileage.

Could go with a single vis oil, or move up to 20-50.

You don't hear knocking or rattle when that happens do you?