Engine Has No Oil Pressure To Lifters Or Rocker Arms

GMC Acadia Emblem

I am having problems with a 2009 Chevy GMC 8.1 engine. The rocker system is not oiling. What causes this and how can I fix it?

Do you have an oil pressure gauge on the dash?

Yes we hooked 1 up 50 pound of pressure idling. 50 PSI at idle is quite high on this motor hot. Are you hearing top engine ticking?

Have you verified no oil at rockers when running with V/cover off? Did this start all of a sudden?

Yes were hearing top engine ticking and with valve cover off we see no oil…not really sure when it started but it was pretty sudden

OK. Let me look at a few things…

Ok no problem Ill be here lol.

I was looking for service bulletins and only came across one about 1 or more lifters sticking. But is would have to be all of them if no oil to any. That would be very unlikely. Other than that, aeration of the oil could cause this. That again could be from one or more lifter. Since it is under warranty, i would suggest taking it to dealer to evaluate it for that bulletin.

It is not under warranty. I am having this problem on a rollback my uncle and I are trying to fix. It has roller lifters. Oil not coming through push rods.

Over 100k miles? HMM. That bulletin was for AFM only. Then there must be a blockage somewhere. Even though not AFM, the AFM manifold is on the engine. Maybe a blockage there.

Yes over 100k what is hmm.

Hmm. The bulletin is only AFM lifters, not roller. Got me stumped on this one.

Maybe a spun cam bearing, restriction somewhere, etc. Sound like tearing it down is the next step.

Thank you that’s what we were thinking.

Let us know what you find…

We will thank you.