Lifters not getting enough oil?

SilverSulley · July 30, 2015

My oil pressure went haywire, so I read through a couple of great write ups on here and swapped out the oil pressure sensor. It seemed to fix the "issue" for 2 months. Last week I was driving back from Memphis and the lifters started to make a ruckus. I pulled over checked my oil and added a little. Afterwards, it fixed the lifter noise but I noticed the gauge was going from 80 to 20 and back and forth. I didn't have an issue with the lifters again until yesterday after a 10 mile drive. Again, just a little bit of oil had calmed them down. Which makes me think that they aren't getting enough oil... So last night I fished out the screen underneath the sensor unit because I didn't realize there was one in the hole the first time around and it is spotless. As I wait for a new sensor is there something else I can check? My buddy is going to bring by some oil pressure gauges so I know exactly where I stand, but right now I'm scratching my head. Any help would be greatly appreciated. I am running the Vortec 5.3L with 140,000 miles.

ifixedit · July 30, 2015

I just read this post with interest, sounds like you may be experiencing the same problem but looks like you already saw it. >>> http://www.gm-trucks.com/forums/topic/169782-attention-anyone-with-oil-pressure-issues/

When it makes the noise is there oil registering on the dip stick? Does the check engine oil message come up? It's a bit odd it quits doing it when you add more oil which seems to point to it either being seriously low on oil, but the more likely culprit is the pump is starving / cavitating which would cause a drop in oil pressure and hence the noise. The only thing I can think of and I've seen it happen is the oil pickup tube (or part of it) falls off the pump and ends up in the bottom of the pan, thus it can't pick up oil once it gets so low. If you know for sure you have at least 4 quarts of oil in it when it does this, I'd be dropping the oil pan and soon to investigate if the the pick up or part of it has fallen off. If what I suspect is happening, this isn't just a lifters not getting enough oil situation, this is a whole engine not getting enough oil situation which could cause serious damage to bearings as well, mains, rods, cam, cam lobes, lifters, the whole works. I wouldn't even drive it unit you figure it out.

CapitalTruck · August 3, 2015

I just read this post with interest, sounds like you may be experiencing the same problem but looks like you already saw it. >>> http://www.gm-trucks.com/forums/topic/169782-attention-anyone-with-oil-pressure-issues/

When it makes the noise is there oil registering on the dip stick? Does the check engine oil message come up? It's a bit odd it quits doing it when you add more oil which seems to point to it either being seriously low on oil, but the more likely culprit is the pump is starving / cavitating which would cause a drop in oil pressure and hence the noise. The only thing I can think of and I've seen it happen is the oil pickup tube (or part of it) falls off the pump and ends up in the bottom of the pan, thus it can't pick up oil once it gets so low. If you know for sure you have at least 4 quarts of oil in it when it does this, I'd be dropping the oil pan and soon to investigate if the the pick up or part of it has fallen off. If what I suspect is happening, this isn't just a lifters not getting enough oil situation, this is a whole engine not getting enough oil situation which could cause serious damage to bearings as well, mains, rods, cam, cam lobes, lifters, the whole works. I wouldn't even drive it unit you figure it out.

What an interesting theory. Never would have thought of that (re: oil pickup tube gone bad).

Duelin · August 3, 2015

Some times when the pickup tube is assembled to the pump the o-ring will get nicked. Then when the engine get higher mileage on it the nick will start to get bigger from deterioration which will allow it to suck air.

ifixedit · August 3, 2015

Your truck was probably built on a Monday or a Friday! Yep, get in and get a look at that pump pick-up assembly asap, I'd just about guarantee something with it is at issue.

SilverSulley · August 7, 2015

Thanks for all of the great feedback, she is going to soak up some sun until I take her in to the mechanic on Tuesday. I am starting to regret purchasing the 5.3L Vortec due to the laundry list of issues that comes with it but I guess that is part of ownership.