Ok, I wasn't real sure where to post this so I thought I'd try here first. My dad has a '99 Silverado, 5.3. Its got 300K+ miles on it, he's driven the crap out of it. Anyway, he said that after it sits for a day that when he goes to start it up there is no oil pressure for 10-15 seconds. His question is, is there a check valve in the pump or is the pump failing? Don't have any clue how long this has been happening so it could have just started or been happening for the last year. Any thoughts or suggestions?

 

Your sender could be dirty after that many miles....Or gauge could be bad....Or short in the gauge....Does the motor make alot of noise when it is started?...Cause of no oil...Or is it quite