5.3 oil pressure

[Jh1984oh1]

Hello everyone
Got an 06 envoy Denali 186000 roughly 5.3 upon startup oil pressure rises like normal but then falls down to 0 shut off motor etc when this happens engine starts clacking give it sone gas noise goes away and oil pressure goes up but it will only stay normal once vehicle is up to temp doesn’t make a sound purrs like a kitten I’m starting with oil pressure switch anyone have any other ideas other then oil pump?

 

[TollKeeper]

I would start with checking the oil pressure with a mechanical oil pressure guage.

That being said, with the noise you are describing, it sounds like a drop of the oil pan is in your future. The oil pickups are known to get clogged, and as memory serves (I could be wrong), the O-Ring on the oil pick up is a known problem.

 

[Jh1984oh1]

Thank you for the reply what do you think about sea foam? I’m not crazy about solvents n whatever I’m my engine big my times limited working 70-80hrs a week

 

[TollKeeper]

I have had good luck with seafoam thru the intake. Never used it anywhere else.

 

[Jh1984oh1]

Ok thanks for the help I’ll give it a try in a week if it dies t work it’ll be a cheap truck for someone that wants to fix it or swap motors thanks again much appreciated