Low Oil Pressure

[XLDenali11]

Hello all. As the title suggest I am having issues with low oil pressure. I have an AWD 11 Yukon XL Denali with about 188k on the clock. I have not noticed any issues with the drivability whatsoever but will see readings when at hot idle of about 17psi. She still gets to 6k rpm with no issues at all. I have no lights on the dash other than tpms. After reading through multiple threads the most common issue that I noticed was the oil pump o ring. I went ahead and swapped the o ring along with a new pan gasket and radiator fittings that were previously leaking but am still getting the same readings. According to just about every forum, that pressure is still within range but wanted to get some insight. Time for new Oil pump? Thank you in advance.

 

[Foggy]

Probably be just fine... What is your cold start up psi, hot running down the road at 2K rpm psi, and max
psi when up in the rpms ?????

 

[Marky Dissod]

... having issues with low oil pressure ... AWD 11 Yukon XL Denali ... 188k ...
have not noticed any issues with the drivability whatsoever, but will see readings when at hot idle of about 17psi.
She still gets to 6k rpm with no issues at all. I have no lights on the dash other than tpms.
After reading through multiple threads the most common issue that I noticed was the oil pump o ring.
I went ahead and swapped the o ring along with a new pan gasket and radiator fittings that were previously leaking but am still getting the same readings.
According to just about every forum, that pressure is still within range but wanted to get some insight. Time for new Oil pump? Thank you in advance

Switch to 0w30 or 5w30 yet? How often do you change your oil?
Your Engine Half@$$ system may be bleeding off some oil pressure, even if it is disabled.
When Engine Half@$$ is physically deleted with the full and proper kit oil pressure tends to rise a bit.
Someone will come by with a better idea, just checking.

 

[Dustin Jackson]

@XLDenali11 That sounds fine to me, mine idles under the first line and gets around 40 when driving around.

 

[donjetman]

there is nothing wrong

 

[Joseph Garcia]

IMO, that idle pressure, while 'somewhat normal' is a bit on the low side, and if it gets any lower, I'd be concerned.

What is the pressure at 1500 and 2500 rpms?

You probably did not replace the oil pressure relief valve in the oil pan while you were in there, but that was the source of my low oil pressure issue. I acted, because my hot oil pressure was only 20 psi at 2000 rpms.

 

[SpareParts]

After having a few 07-09 6.2 engines with over 150k im a firm believer that if they have lowish oil pressure the cam bearings are probably shot.
A guy can band aid it with a new O ring and HV oil pump but it still has bad cam bearings.

 

[Joseph Garcia]

After having a few 07-09 6.2 engines with over 150k im a firm believer that if they have lowish oil pressure the cam bearings are probably shot.
A guy can band aid it with a new O ring and HV oil pump but it still has bad cam bearings.

Why should the 2007-2009 6.2L motors have bad cam bearings? I could see 5.3L motors with AFM added in 2007, but the 6.2L motors, like the OP has did not have AFM until 2010. Just curious in what supports your statement.

I changed my cam at 160,000 miles when I installed the supercharger, just because (I ordered the new cam before I inspected the existing cam), but my existing cam was in great shape.

 

[thefrey]

What is your cold start and cruising pressure?

A new oil pump could help. The acceptable oil pressure for GM's spec is kind of crazy, I believe it's close to 6psi. I don't know if I would lose sleep over 17psi hot. It is on the lower end IMO but well within spec, I would say most stock high mileage motors idle around there from what I see.

Mine used to idle between 12-17psi hot at 215k miles. A new HV oil pump brought it up to 22-25 idle along with a DOD delete.

There are a lot of spots where oil seals can leak internally on DOD motors... the VLOM, camshaft retainer plate, barbell in the rear. A DOD delete will address 2 out of the 3.

If you are going to put a new pump in, it may be worth considering a new camshaft retainer plate. I don't know if it'll give you much benefit, others who are more knowledgeable than I can chime in, but it might be worth a "while you're in there" especially if you are thinking about putting a new timing chain on.

 

[SpareParts]

There is very little supporting the #2 cam bearing. Only about .160 on each side of the center cut out. #1, 2, 3 bearings are usually the worst.
Look at the pics you can see the ware pattern on the cam and bearings.

 

[SpareParts]

I should add about my thinking.
The AFM is not the cam bearings problem. The VVT is the problem with original short bearings.
AFM wiping out the cam is from a failed lifter, not bearings.
They are 2 different failures.
The original cam bearings are not long enough to fully support the cam in any of the 5 cam journals either.
That is the reason to install the longer 1 piece CH-25 bearings if you do cam bearings.
A new non VVT cam rides on the previously unused portion of the #2 bearing (the unused center part). Maybe it is supporting the cam better now then when new?
A used VVT non AFM cam when removed is usually good and can be reused but should be polished if reusing.
I could be totally wrong cuz im a dumbass, but from my experience i believe im right.

 

[XLDenali11]

Cold startup psi sits just above 40 and gets higher while driving. Once it gets hot it will idle between 17-20 and will go up to about 30 at 1800 rpm. When I really get on it, it will go slightly above 40. I am not to worried about it as it still drives like a champ. Oil changes are always done within 5k miles and with 5w-30. Now that I think about it, I don't remember seeing the pressure relief valve. I have AFM tuned out through a BBP tune but have not done actual DOD delete, on the list of things to do. Would swapping the cam be worth it at 188k without knowing how well it was maintained before me? I have read on a few threads that cam bearings were an issue from 07-10 but were addressed by 2011.

 

[swathdiver]

Cold startup psi sits just above 40 and gets higher while driving. Once it gets hot it will idle between 17-20 and will go up to about 30 at 1800 rpm. When I really get on it, it will go slightly above 40. I am not to worried about it as it still drives like a champ. Oil changes are always done within 5k miles and with 5w-30. Now that I think about it, I don't remember seeing the pressure relief valve. I have AFM tuned out through a BBP tune but have not done actual DOD delete, on the list of things to do. Would swapping the cam be worth it at 188k without knowing how well it was maintained before me? I have read on a few threads that cam bearings were an issue from 07-10 but were addressed by 2011.

Yours sounds like mine. For the past year she was slow to build pressure on start up and once warmed up came down from 25 psi or so hot at a traffic light to a low of 18 psi. We replaced the o-ring the other night and the rattle is gone but hot low oil pressure still exists. That's probably the cam bearings on this 221K mile motor. LS engines are ******* them compared with other engines. Motor has to come out to change them.

The 25 psi readings were from years ago, she's slowly but steadily been declining. Oil samples all come back great.

MY plan is to keep driving it and someday replace the 5.3 engine with a 6.2 that I build.

 

[thefrey]

Would swapping the cam be worth it at 188k without knowing how well it was maintained before me?

I did my DOD delete at 215k. I bought my Yukon with 198k and I have no good idea of how well it was maintained before me.

Your oil pressures were almost identical to mine after I did my o-ring and before I did a DOD delete. New stock profile non-afm cam.

Pre delete I was around 45psi cold, 32 cruising, and around 15ish idle. Now I am 60-70psi cold start, 40-45 cruising, and about 25 when hot with a Melling HV pump.



How much gunk was at the bottom of the oil pan when you changed it? That could be a possible indicator of how well it was maintained before.

Something you could also do is send your oil off for analysis to give you a better idea of the health of your engine. Might be worth the $40-$50 bucks for peace of mind before you put money into it.


Are you hearing any noises at all?

All depends on how much longer you're wanting to keep the vehicle. IMO you are probably just fine to keep driving with the DOD turned off assuming you aren't having any abnormal noises. I had a persistent tick that wouldn't go away hot or cold and that's what pushed me to finally do a DOD delete. I was under the assumption it was a lifter tick which it probably was. I had no idea until I got the heads off, but I had a cracked piston and I think the last owner knew and put it up for sale... lol. Not to say that to scare you since that’s a definitely one off type situation, but many people drive with DOD turned off (or not turned off at all) and make it well above 200k. The DOD delete is worth it to a lot of people just for the peace of mind and reliability.

 

[catalinajack]

I did my DOD delete at 215k. I bought my Yukon with 198k and I have no good idea of how well it was maintained before me.

Your oil pressures were almost identical to mine after I did my o-ring and before I did a DOD delete. New stock profile non-afm cam.

Pre delete I was around 45psi cold, 32 cruising, and around 15ish idle. Now I am 60-70psi cold start, 40-45 cruising, and about 25 when hot with a Melling HV pump.



How much gunk was at the bottom of the oil pan when you changed it? That could be a possible indicator of how well it was maintained before.

Something you could also do is send your oil off for analysis to give you a better idea of the health of your engine. Might be worth the $40-$50 bucks for peace of mind before you put money into it.


Are you hearing any noises at all?

All depends on how much longer you're wanting to keep the vehicle. IMO you are probably just fine to keep driving with the DOD turned off assuming you aren't having any abnormal noises. I had a persistent tick that wouldn't go away hot or cold and that's what pushed me to finally do a DOD delete. I was under the assumption it was a lifter tick which it probably was. I had no idea until I got the heads off, but I had a cracked piston and I think the last owner knew and put it up for sale... lol. Not to say that to scare you since that’s a definitely one off type situation, but many people drive with DOD turned off (or not turned off at all) and make it well above 200k. The DOD delete is worth it to a lot of people just for the peace of mind and reliability.

The problem with of these replies? No mention of the possibility that the pressure sensor has malfunctioned. It happens.

 

[CLSVT]

I’ve never been comfortable relying on the dashboard oil pressure gauge. Isn’t there a more accurate means of measuring the oil pressure?

 

[thefrey]

Isn’t there a more accurate means of measuring the oil pressure?

The way most people suggest on this forum is to put a mechanical gauge on and you can tape it to your windshield to see better than what the gauge would do.

I am somewhat surprised because that’s usually one of the first replies to something like this lol.

 

[Joseph Garcia]

The way most people suggest on this forum is to put a mechanical gauge on and you can tape it to your windshield to see better than what the gauge would do.

I am somewhat surprised because that’s usually one of the first replies to something like this lol.

Yes, ABSOLUTELY! Before firing the parts cannon, you NEED to CONFIRM your real oil pressure and the accuracy of your current oil pressure sensor. This can only be tested/achieved by using a mechanical oil pressure gauge.

 

[RET423]

The way most people suggest on this forum is to put a mechanical gauge on and you can tape it to your windshield to see better than what the gauge would do.

I am somewhat surprised because that’s usually one of the first replies to something like this lol.

I also see the sensor advice regularly, but I can't remember anyone ever saying that their consistent readings of oil psi range turned out to be significantly different than when measured with a mechanic gauge

It's easy to put a mechanical gauge off the pan so I do it but if the dash gauge is changing with steady RPM increases & decreases it has always done so on the mechanical gauge as well with similar pressure readings in my experience

 

[SpareParts]

I have changed a few leaking sensors. Never changed one that was not reading properly. Not saying it can not happen because it sure can but i think it is fairly rare.