2007 Yukon Denali low oil pressure

[Chris2144]

So I know there are a lot of threads regarding this but I wanted to ask a few questions and maybe some can help me.

I have a 07 Yukon Denali 6.2 6l80 163k miles I have an oil consumption issue and a low oil pressure issue.
for the oil pressure it is about 45-50 cold start.
Hot idle 15-20
Hot cruising down the road 30-35
It just seems a little low.
I have replaced the pickup tube o ring
Rear main seal
I also just did the vlom gasket and orings, couldn’t really tell much of a difference.
It does have the slightest lifter tick at hot idle. From everything I’ve read I need to check the cam retainer plate and vvt for leaks. It has no codes at all.

On the oil consumption issue I have replaced the driver side valve cover with the updated style. I have also installed a catch can.

I am wondering though the catch can I bought has the inlet going through the baffle with the steel wool pad and the outlet going to the manifold for vacuum.
This seems opposite to me if the catch can starts filling up it would be easy for it to suck up oil just wondering if anyone else has the same one. It’s the evil energy off of Amazon.

I have drove about 500 miles and it already has a little built up so I definitely haven’t cured the consumption problem I got some
Moto medic and I’m going to do the piston soak hopefully that will cure most of the consumption issue

 

[SpareParts]

Could be a bad sender.
I will bet on bad cam bearings for the low oil pressure. A Melling HV oil pump will band aid the problem for a long time or a short time, No way to know.
Someone will tell you to check the screen under the oil pressure sensor. Non AFM 6.2s do not have one.

 

[Chris2144]

Yea so no screen.
Sender tracks pretty close to actual pressure.

If the pressure stays where it is I’ll be ok with it just seems a little low.

I may throw a new pump on if it gets any lower.

Really need to do the piston soak so I can cure the consumption issue

 

[donjetman]

@Chris2144
Your oil pressure is good. No worries

I did the TSB 10-06-01-008M valve cover and piston/combustion chambr soak 7+ yrs and 78k miles ago to our 07 Denali 6.2L which cured the oil comsumption. CC that only collects 1-2 oz per 5000 miles.
It now has 208k miles, and only consumes 1/4 qt per 5000 miles. No leaks.
Here is one of many threads I did back then: https://www.tahoeyukonforum.com/thr...tor-oil-consumption-tsb-10-60-10-008m.108493/

 

[SpareParts]

15 psi at hot idle is a little lower than i personally would like. Some will say it's fine. I would not worry too much about it. Just watch it and see what happens. If you start getting Stabilitrack warnings and check engine light you might have serious oil pressure problems.
I have had 4, 6.2s with under 20psi hot oil pressure and gets lower in summer heat hot.

1: Escalade, had about 15 PSI at hot idle. Put a HV pump in it and a few months later the engine died. Had engine replaced. 6ish months later the new engine was loosing oil pressure and glitter in the oil, traded it with the warranty paperwork.

2: Escalade, had about 12 PSI hot oil pressure and glittery oil. Pulled engine and installed new cam bearings. Stock oil pump used. Oil pressure seemed to be holding steady at 25ish hot idle for the 8ish months i owned it.

3: Denali, friend of a friend's truck. Hot oil pressure was 12ish psi hot idle. Put a new HV oil pump in it and hot idle oil pressure was 20ish psi. Still going as far as i know.

4: Denali: My current wrecking yard engine. Installed new cam bearings before i put it in my truck. Glad i looked at em as they were shot. Stock oil pump and hot idle oil pressure is 25ish.

5: The old engine out of my truck had shot cam bearings. Engine getting rebuilt.

Anyway, that's my experience with old 6.2s. O rings cures some and the ones a new O ring does not fix its cam bearings, its always cam bearings.

 

[Chris2144]

Well should I just plan on putting a hv melling pump in it?

The catch can still seems odd it says inlet on it and that is going to the baffle with the steel wool the outlet is going to the manifold so it seems it would be easy for the engine to still suck up oil that way. I think I’m going to switch it.

Hopefully this piston soak will cure the consumption problem.

On top of that I have a rough idle I’ve been tracing. Had a vacuum leak from the pcv line and just replaced intake gaskets when I did the vlom has made no change. Ltft where high like 9-10 both banks.
No codes and it runs great.

Just want it to be reliable

 

[Marky Dissod]

Just want it to be reliable.

Then you need to find a way to check the cam bearings. At least do a used oil analysis ...

 

[thefrey]

Did you notice any difference with psi doing the pickup o-ring?

I had a tick I was chasing for awhile. When I replaced my o-ring, it gave me another 3-5 psi but didn't fix my tick. Funny enough I think replacing my o-ring made my AFM work more and made a lifter collapse lol. anyways...

I ended up doing a DOD delete and put new lifters, camshaft, camshaft retainer, etc in. I did install a Melling HV pump.

I went from 45 ish cold start, 28-35 hot cruise, and 12-20psi hot idle to now 60-70psi cold start, 40-45 hot cruise at about 70-80mph, and 20-25 hot. This is with the stock spring in my HV pump. I have 221k on my motor now.

Personally, I think your oil pressures as is are okay, but I am no certified mechanic. The low oil pressure light doesn't even come on until I think 7psi at idle. Your numbers sound pretty good IMO for a motor at its age.

Check oil pressures with a mechanical gauge to confirm before you do anything as others have said.

 

[Joseph Garcia]

I'm not a fan of a hot idle pressure less than 20 psi. Just my opinion.

Your issue could be the cam bearings, and sending a used oil sample to Blackstone Labs would be a great option for you at this time to get additional information on the state of your motor.

You replaced your O-ring, and I trust that it was the correct one.

There is also an oil pressure relief valve inside the oil pan, and they can get partially clogged over time and not totally close, thus reducing oil pressure. And, with your L92 motor, that pressure relief valve is not necessary (no AFM) and can be deleted. This was my experience. The O-ring was replaced, and the low oil pressure did not go away. The oil pan was removed again and the oil pressure relief valve was replaced with a delete plug. I also put in a Melling HP/HV oil pump, at that same time. My oil pressures are now phenomenal, but I can't tell you for sure if it was the oil pressure valve delete or the Melling oil pump, or both.

 

[Chris2144]

I did not replace the the relief valve I may have to look into that.
The cam bearings make sense I may do lifters cam springs if the pressure gets any lower.

As for the oil consumption I am doing the piston soak right now I got some of the motor medic and it is sitting in there I’m going to turn the engine and put some more in after a few hours.
Hopefully that cures the oil consumption.

I have pulled a few ounces of oil out of the catch can twice in the last 1k miles

Also these spark plugs have 5k on them

I put a pic of the catch can setup I think I’m going to switch the hoses around

 

[Joseph Garcia]

I did not replace the the relief valve I may have to look into that.
The cam bearings make sense I may do lifters cam springs if the pressure gets any lower.

As for the oil consumption I am doing the piston soak right now I got some of the motor medic and it is sitting in there I’m going to turn the engine and put some more in after a few hours.
Hopefully that cures the oil consumption.

I have pulled a few ounces of oil out of the catch can twice in the last 1k miles

Also these spark plugs have 5k on them

I put a pic of the catch can setup I think I’m going to switch the hoses around

I can't tell from your photo, but does the 'IN' hose go to the valve cover, and the 'OUT' hose for to the the intake manifold?

 

[Chris2144]

Yes that’s how it it routed. The problem is inside the can there is a screw on baffle over the port of the IN side that has some steel wool in it.

The other side that goes to the manifold is just open which would make it easy to suck up oil.

 

[SpareParts]

I would leave it as is. That bronze filter(?) on the in port will filter the incoming air and help to collect the oil mist. Once it's soaked with oil it drips out.
On the suction side the oil would get sucked into the engine. I would think anyway.

 

[Chris2144]

Hmm that does make sense. It does appear to be working I’ve pulled about 8 ounces out in the last 1k miles.
Hopefully this piston soak will cure the consumption. In a little while I will clear the cylinders and put everything back together then change the oil.

 

[Marky Dissod]

Point of a catch can is to give oil vapors space and time to condense and separate.
Hopefully the engine gets the fractions of the oil vapors (as well as fuel vapors) that remain gaseous when given a chance to cool,
while the oil vapor fractions that more easily condense to liquid get trapped by the catch can.
(Which is why catch cans should be WIDER, and should be protected from heat ...)

 

[Joseph Garcia]

Yes that’s how it it routed. The problem is inside the can there is a screw on baffle over the port of the IN side that has some steel wool in it.

The other side that goes to the manifold is just open which would make it easy to suck up oil.

You're OK as you are. If you keep the catch can below 3/4 full, the captured oil is heavy enough that it won't get sucked upward in the catch can and into the intake manifold.

 

[Chris2144]

I’ll leave it like it is then.
Im about to go empty the cylinders from the piston soak and put it back together.

 

[Chris2144]

Well piston soak is completed.
Got it back together and started it up it made some funky noises for a min and smoked an insane amount.
Let it run for a few mins then shut it off and changed the oil and filter.
Engine seems to idle a bit smoother now and seems a bit quieter.
We will see how much oil accumulation I have in the can over the next week

 

[donjetman]

@Chris2144
The point of the new improved valve cover TSB link is to do a good job of NOT allowing oil to make its way out of the valve cover with or without a catch can.

My cheap amazon catch can caught a lot of oil until I did the TSB 7 yrs and 75k+ miles ago. Only collects 1-2oz every 5k miles since I did the TSB.

 

[Chris2144]

Well even with the new valve cover the catch can was still pulling out oil so that’s why I did the piston soak.
Hopefully now I won’t have any oil coming through.