L92 low hot oil pressure at idle HELP!!!!

[kbuskill]

How difficult is it to replace that o-ring?

Depends on the truck.

2wd = unbolt steering rack and let hang, drop crossmember and pan, unbolt pickup tube and replace O-ring. There is probably some other little details I'm forgetting as it has been a while since I did it.

4wd requires dropping everything mentioned as well as the front differential.

When I did mine I went ahead and pulled the front timing cover and replaced the pump and timing set as well because I was already that far in.

 

[Campie]

How difficult is it to replace that o-ring?

Depends on the truck.

2wd = unbolt steering rack and let hang, drop crossmember and pan, unbolt pickup tube and replace O-ring. There is probably some other little details I'm forgetting as it has been a while since I did it.

4wd requires dropping everything mentioned as well as the front differential.

When I did mine I went ahead and pulled the front timing cover and replaced the pump and timing set as well because I was already that far in.

Oh my… of course it’s the all-wheel Denali. Maybe I’ll try a heavier weight oil? Thanks for your help!

 

[j91z28d1]

Oh my… of course it’s the all-wheel Denali. Maybe I’ll try a heavier weight oil? Thanks for your help!

do the test first.

add 2 extra qt of oil, park down hill. this covers the o ring in oil and if bad, the oil pressure would be higher. Just don't drive with the extra oil.

the o ring is like the default answer to low oil pressure but honestly, it you follow these forums for a few years, you'll see very few that actually get fixed from just changing o ring. most have to go back in and change to a higher volume oil pump to cover for whatever is actually causing it. I pulled a 110k o ring out of a ls3 engine that's been abused it's whole life and the o ring was perfect. I only changed it because I was doing a leaking pan gasket. my 170k yukon hasn't been opened yet. oil pan gasket of course leaks because gm somehow found rubber gaskets and aren't oil resistant lol.

but yeah, good luck.

 

[Campie]

do the test first.

add 2 extra qt of oil, park down hill. this covers the o ring in oil and if bad, the oil pressure would be higher. Just don't drive with the extra oil.

the o ring is like the default answer to low oil pressure but honestly, it you follow these forums for a few years, you'll see very few that actually get fixed from just changing o ring. most have to go back in and change to a higher volume oil pump to cover for whatever is actually causing it. I pulled a 110k o ring out of a ls3 engine that's been abused it's whole life and the o ring was perfect. I only changed it because I was doing a leaking pan gasket. my 170k yukon hasn't been opened yet. oil pan gasket of course leaks because gm somehow found rubber gaskets and aren't oil resistant lol.

but yeah, good luck.

Ok, for clarity, I add 2 extra quarts of oil, point it down into a ditch - how far down? - and start it up and watch the oil pressure? But then I have to drain out that extra 2 quarts before I drive any distance?

 

[j91z28d1]

Ok, for clarity, I add 2 extra quarts of oil, point it down into a ditch - how far down? - and start it up and watch the oil pressure? But then I have to drain out that extra 2 quarts before I drive any distance?

yeah. I don't know exactly how far down in deg it has to point as it's not way above the oil line. I get the feeling 2 qt of oil is almost enough to cover it on flat ground. but yeah, going from idle on flat ground to nose down and watch the gauge to see if it comes up.

 

[Campie]

Ok, for clarity, I add 2 extra quarts of oil, point it down into a ditch - how far down? - and start it up and watch the oil pressure? But then I have to drain out that extra 2 quarts before I drive any distance?

I’ll also check what weight oil it has in it now now and verify the level. Thanks!

 

[rdezs]

Two extra quarts of oil, and most floor jacks under the rear differential raised all the way will be more than enough.

 

[Smulvey585]

2 Month since I changed to 15-50 Mobil 1 Oil.
No more tickng at startup at all.
Oil Pressure begins at 51 PSI and declines to 35 PSI
This is the same as I had on 5-30 Oil but I had a lot of ticking from possibly 1 or 2 lifters.

I am going forward with the better oil and I am going to get a block heater for this winter.
I am semi retired and start out from home virtually all trips so I think this is my plan to get to mileage of 200,000 before I die. I only drive 5-7 ,000 miles a year.

Hate to have to rebuild the truck at this point. I am at 100,000 miles now.

The crankshaft issue should not effect me since I am a 2014 and presume I do not have the Mexican made crankshaft.

 

[rdezs]

2 Month since I changed to 15-50 Mobil 1 Oil.
No more tickng at startup at all.
Oil Pressure begins at 51 PSI and declines to 35 PSI
This is the same as I had on 5-30 Oil but I had a lot of ticking from possibly 1 or 2 lifters.

I am going forward with the better oil and I am going to get a block heater for this winter.
I am semi retired and start out from home virtually all trips so I think this is my plan to get to mileage of 200,000 before I die. I only drive 5-7 ,000 miles a year.

Hate to have to rebuild the truck at this point. I am at 100,000 miles now.

The crankshaft issue should not effect me since I am a 2014 and presume I do not have the Mexican made crankshaft.

With only 100,000 miles, next oil change try scaling it back to a 10w40 full synthetic and see what your oil pressures are. I think the 50 weight might be a little risky for the VVT components, as well as the bearings overall. I really think a 10w40 and turning off the AFM either with a disabler that plugs into the OBD2 port or an ECM tune.... Most likely will make it to 200,000 miles.

I suspect the biggest factors in your oil pressure issue is probably the result of waiting on oil changes until it tells you it's due.... That has probably compromised your camshaft bearings to some extent. I would not go more than 4,500 miles between oil changes, 3,500 if mainly city driving.... That will help you reach your goal of 200,000.

Not much you can do to extend the life of the oil pickup tube o-ring. That's something that eventually you will be dealing with between now and 200,000. (Quite possible and probable that is the issue with the oil pressure) If you have at least 20 psi idling hot and drive, headed highway speeds cruising it's in the mid 30s.... That's about right for a stock 6.2 with some miles on it. (With 5W30)

On a side note, my program now at the AFM on my wife's 2014 Escalade at around 100,000 miles if I remember right. Did the full AFM delete last year at 172,000 miles. All the lifters looked pristine. It did get the o-ring on the pickup tube replaced at 120,000 miles.... And recovered 5 PSI at a hot idle at that time.

 

[Smulvey585]

I bought this used via a used car dealer / the Manhiem Auction in PA and a Cadillac Dealer trade in in PA. the unit was originally in colorado with a rental company. I bought it at 68,000 miles.

I do have a disabler installed on the OBDC port.

The low temperatures will require me to drop back on the oil weight this winter.
Even with the block heater.

 

[rdezs]

You might actually increase bearing wear with a 50 weight oil. Particularly when cold, it's going to take a while for the oil to get where it needs to. It's also going to hang out in the bearing longer than a thinner oil, increasing bearing temperatures. (A 5W-30 flows a lot more, taking a lot of the bearing heat with it)

Just my thoughts....

 

[j91z28d1]

a user here has tested everything from 0w20 to 50w with meticulous testing along with way. zero problems or increased wear

it's fine to run 15w50. especially if it sound better. give it what it wants.

@donjetman

 

[rdezs]

In an AFM engine with VVT? Oil viscosity is important to the functioning of the variable valve timing...... But okay.

 

[donjetman]

My 200k mile 07 6.2 L92 w/VVT and no AFM could care less about oil viscosity, but I don't hotrod it or tow.

 

[Campie]

My 200k mile 07 6.2 L92 w/VVT and no AFM could care less about oil viscosity, but I don't hotrod it or tow.

Ok so what oil should I go to? 2007 Yukon Denali 6.2, 156k. Starts at 50 cold and goes down to about 10 at hot idle. It’s running 5w30 now. I tried the nose-down test and got maybe a tiny bit of change but hardly noticeable.

 

[rdezs]

10 psi at hot idle would make me nervous. I'd want to verify that with a mechanical gauge, it could be your sending unit is going bad.

And if the 10 psi figure is accurate, that's worth pulling the front cover at least to open up and check the oil pressure relief valve in the oil pump. I would just go ahead and replace the oil pump. You get to take care of the new o-ring on the pickup tube at the same time.

It's not uncommon for the OEM oil pumps to build up a certain amount of crud in the relief valve and affect its ability to work.

If you're looking to just keep it going on a tight budget but want more pressure, I would start with a 10w40 oil if you want to go that route with a higher viscosity. And then with each oil change, if you're looking for more pressure, increase viscosity incrementally.

 

[donjetman]

Ok so what oil should I go to? 2007 Yukon Denali 6.2, 156k. Starts at 50 cold and goes down to about 10 at hot idle. It’s running 5w30 now. I tried the nose-down test and got maybe a tiny bit of change but hardly noticeable.

until a used oil analysis report indicates there's a problem, there isn't a problem.

If you want more oil hot oil pressure? run a xx-40, xx-50, or xx-60 viscosity oil for more pressure.

More importantly for that yr model L92 and 6L80, has GM TSB 10-06-01-008M been done? https://static.nhtsa.gov/odi/tsbs/2014/MC-10114272-9999.pdf

and has the torque converter been replaced?

 

[donjetman]

 

[Charlie207]

My 200k mile 07 6.2 L92 w/VVT and no AFM could care less about oil viscosity, but I don't hotrod it or tow.

This is why they say you should wait a heat-cycle before doing all the burnouts, yeah?

 

[Campie]

until a used oil analysis report indicates there's a problem, there isn't a problem.

If you want more oil hot oil pressure? run a xx-40, xx-50, or xx-60 viscosity oil for more pressure.

More importantly for that yr model L92 and 6L80, has GM TSB 10-06-01-008M been done? https://static.nhtsa.gov/odi/tsbs/2014/MC-10114272-9999.pdf

and has the torque converter been replaced?

Yes, oil analysis is next and I’ll up it from 5W 30 to 5W 40 til we get a better idea of what the issue really is.

Hummm… no and no to your suggestions. I’ll look into both! Thank you!