Not sure what happened. Its got 95k miles on it and the engine has had zero issues. Out of nowhere i starting having the oil pressure issue.

When you start the truck everything is good and normal when cold, but after running for about 5 minutes the pressure will start to drop.

When the pressure is good and you rev the motor it raises as it should

it slowly starts to drop and when you rev it then the pressure does not raise at all.

The pressure will go all the way down to zero.

The weird thing is that when you shut the engine off and restart it the pressure is normal for a short period of time before it drops again.

any ideas?

 

Not trying to point out the obvious but the oil is full right?

 

yes the oil is full.

when I get time i'm going to put a mechanical gauge on it, but due to the symptoms being not very irregular I don't think it would be the gauge, but I'll still test it when I get a minute here.

 

Yes, use a mechanical gauge first. That will tell you if the sender or cluster is bad.

 

Oil pump or oil pressure sender! Had some of these come through the shop. There was a bulletin pertaining to the oil pump. Relief valve in the pump is hanging open. Also had a bunch of oil pressue senders bad too and under that is a screen that gets plugged if they don't change their oil. It would be great if you could check the oil pressue. If the lifters start rattling when it has no pressure then you know the sender is probably fine.

 

i get no rattling at all. Is that screen easy to get out? What about just removing it completely?

 

Yeah you can just use a pick, hook it, and pull it out. A new one isn't much at all. I'd probably bet you've got a bad oil pressure sender.

 

Way back in the day my engine lost oil pressure and it did not rattle. Oil with silverish tint on the dipstick confirmed that there was no oil pressure.

 

Are the lifters ticking when this occurs.

 

put a mechanical gauge on it and readings were the same. Did a oil and filter change and everything seems perfect. What a weird thing