Low Oil Pressure at Idle When Warm

[Austen Leach]

Your sucking oil thru your pcv is my bet. At high speed cruising.

So are you thinking I might need a new PCV valve? Or the whole valve cover due to the baffle in it? How do you recommend checking it all out?

 

[avalonandl]

Try a cheapo catch can....is one way.....

 

[Austen Leach]

Try a cheapo catch can....is one way.....

This is probably a separate issue and not related to my low oil pressure issue right?

 

[Austen Leach]

Update to everyone. I swapped the oil pressure switch with a known good switch off my buddy's truck and it still reads low. Looking at replacing the oil pump

 

[Austen Leach]

Another update. I got the whole engine torn apart and was replacing the cam at the same time since I was there you know? Well the cam would only come out about 3 lobes and then it would stick and no matter what I did it wouldn’t move. Took the oil pan completely off and looked up through the block and I had 2 cam bearings stuck on the old cam. This engine didn’t make a single bit of noise at all to point towards any spun bearings and I still had 20psi of oil pressure when it warmed up. Getting a used engine and swapping all my new stuff over to it

 

[Charles Land]

I have a 2004 Tahoe with a 5.3 flex fuel engine and I've started to have low oil pressure issues at idle when hot only. When I start the truck cold the oil pressure is at 40psi and will go higher whenever I touch the accelerator. But as the temperature starts to rise the pressure will slowly bleed off. At 210 degrees the oil pressure is at 20psi and will go up to 40psi at about 1200 rpms. I've already replaced the oil pump pickup tube o-ring thinking that was it and it didn't solve my problems. Anyone have any ideas?

Is the oil pressure at idle steady or does it flutter? If it flutters you are sucking air somewhere.

 

[Austen Leach]

Is the oil pressure at idle steady or does it flutter? If it flutters you are sucking air somewhere.

It was steady sitting at 19-20psi. I pulled everything apart thinking I had a weak oil pump and went to slide the cam out and it wouldn’t budge after 3 lobes

 

[NortheastRig]

This is a great thread and maybe you guys can help me out.

so I have a 06 Denali with the 6.0 engine, 183k miles. Before I got it fixed my oil pressure gauge would read at 80 and occasionally I would get the low oil pressure chime but for the most part the engine ran fine and I didn’t do any extended drives just more so around the neighborhood.

so I finally got around to addressing the oil pressure and I took it to my mechanic, I told him the issue and he looked into it. So he changed out the oil pressure switch, put a new oil pump in(high pressure) and changed out the O-ring, also i changed the oil pan as well.

I got the truck back and the oil pressure went from reading 80 to 40/50 at idle, now here is where it gets concerning. When the engine starts to warm to operating temperature the oil pressure dips to 20 at idle. Now if I drive and oil pressure raises to about 35 and stay there if at a higher rpm but once im stopped at a light the oil pressure will literally go to 0 and the low oil pressure chime will go on and stay on until I start driving again.

I took the truck back to my mechanic where he put it on the computer and showed that the oil pressure at operating level but the gauge is showing 20 when the engine is below 210 and 0 when it’s above 210.

now my mechanic is saying might need replacement engine preferably a remanufactured engine block with a warranty.

I think that’s pretty drastic considering my current engine is very quiet with no noticeable knocks or anything of the sort and he’s quoting me just on the labor alone of taking all my parts on the current engine and transferring them to the new engine long block of about $2500.. The engine alone is going to cost about $2500 with a $610 core

I’m wondering If I should just get a used engine with decent miles and for about $1000 and have it installed instead of buying a remanufactured engine and swapping all the old parts onto the new engine block?

 

[Austen Leach]

This is a great thread and maybe you guys can help me out.

so I have a 06 Denali with the 6.0 engine, 183k miles. Before I got it fixed my oil pressure gauge would read at 80 and occasionally I would get the low oil pressure chime but for the most part the engine ran fine and I didn’t do any extended drives just more so around the neighborhood.

so I finally got around to addressing the oil pressure and I took it to my mechanic, I told him the issue and he looked into it. So he changed out the oil pressure switch, put a new oil pump in(high pressure) and changed out the O-ring, also i changed the oil pan as well.

I got the truck back and the oil pressure went from reading 80 to 40/50 at idle, now here is where it gets concerning. When the engine starts to warm to operating temperature the oil pressure dips to 20 at idle. Now if I drive and oil pressure raises to about 35 and stay there if at a higher rpm but once im stopped at a light the oil pressure will literally go to 0 and the low oil pressure chime will go on and stay on until I start driving again.

I took the truck back to my mechanic where he put it on the computer and showed that the oil pressure at operating level but the gauge is showing 20 when the engine is below 210 and 0 when it’s above 210.

now my mechanic is saying might need replacement engine preferably a remanufactured engine block with a warranty.

I think that’s pretty drastic considering my current engine is very quiet with no noticeable knocks or anything of the sort and he’s quoting me just on the labor alone of taking all my parts on the current engine and transferring them to the new engine long block of about $2500.. The engine alone is going to cost about $2500 with a $610 core

I’m wondering If I should just get a used engine with decent miles and for about $1000 and have it installed instead of buying a remanufactured engine and swapping all the old parts onto the new engine block?

If the gauge was pegged out at 80 most of the time and then dropped off to 0 sometimes he shouldn’t have touched the oil pump in my opinion. I would’ve replaced the oil pressure sensor first and then went from there. It’s quite possible that you spun cam bearings like my engine did because after spinning mine I found out from the local LSX performance shop that it’s super common to happen. We ended up being able to just knock new cam bearings into my engine and then I rebuilt the entire thing and just got it put back in my Tahoe yesterday but now I have no spark and no cranking RPMs so I have to check all my grounds and my crank sensor

 

[Rocket Man]

If the gauge was pegged out at 80 most of the time and then dropped off to 0 sometimes he shouldn’t have touched the oil pump in my opinion. I would’ve replaced the oil pressure sensor first and then went from there. It’s quite possible that you spun cam bearings like my engine did because after spinning mine I found out from the local LSX performance shop that it’s super common to happen. We ended up being able to just knock new cam bearings into my engine and then I rebuilt the entire thing and just got it put back in my Tahoe yesterday but now I have no spark and no cranking RPMs so I have to check all my grounds and my crank sensor

Hoping for a quick solution to your problem, you’ve been through a lot with this engine.