Engine noise? Started w low oil pressure

[SiWilli]

Engine noise?!? 2011 Yukon XL denali with the 6.2. Left work and not even 5 mins in low oil pressure light came on, knocking noise Probably right around being fully warmed up. Pulled right into a shop who told me engine was seized. Oil was full, recently changed myself. Do my changes at 3k or less with quality stuff. Have only owned for 1.5 years but all fluids were changed at purchase and has run like a dream. Engine is obviously not seized. Tried the overfill on hill, didn’t stop. Running a thicker oil now with rislone, which has helped a bit. Pressure is now at 40 on startup and 25 when warm. Would typically take it to my uncle and start taking it apart but he sold his shop and is unable to help me due to recent surgery so no resources to do myself. This is my daily driver and the love of my life Any pointers on the sound or a good gmc knowledge shop in the Worcester, MA area?

 

[FasterBass]

Engine noise?!? 2011 Yukon XL denali with the 6.2. Left work and not even 5 mins in low oil pressure light came on, knocking noise Probably right around being fully warmed up. Pulled right into a shop who told me engine was seized. Oil was full, recently changed myself. Do my changes at 3k or less with quality stuff. Have only owned for 1.5 years but all fluids were changed at purchase and has run like a dream. Engine is obviously not seized. Tried the overfill on hill, didn’t stop. Running a thicker oil now with rislone, which has helped a bit. Pressure is now at 40 on startup and 25 when warm. Would typically take it to my uncle and start taking it apart but he sold his shop and is unable to help me due to recent surgery so no resources to do myself. This is my daily driver and the love of my life Any pointers on the sound or a good gmc knowledge shop in the Worcester, MA area?

Oil pressure is not out of normal range now, is it still knocking? Id say afm failure if the knock went away.

 

[donjetman]

25 psi and 40 psi is normal.

Still knocking???????

 

[SiWilli]

25 psi and 40 psi is normal.

Still knocking???????

Still knocking!

 

[SiWilli]

25 psi and 40 psi is normal.

Still knocking???????

Yes. This video is after the thicker oil. Pressure is up but still a knocking.

 

[Geotrash]

They could very well be separate issues that just happened to coincide with each other. That knocking is at the same frequency as valvetrain noise, so it’s likely a collapsed lifter.

When my oil pressure sensor screen in my 2012 was blocked, I would get the low oil pressure warning only at normal operating temperature. So I suspect that’s the root cause of your oil pressure issue - false indication.

Another possibility is that the loss of oil pressure was real but only momentary and mainly affected the VLOM. In which case there may have been insufficient pressure for that lifter to complete its transition from locked to unlocked or vice versa, causing it to bind. But I can’t think of anything that would cause only a momentary drop.

Yet another possibility is that the low oil pressure indication was correct, but that the root cause was a leaky pickup tube o-ring, causing their to be insufficient oil pressure for that lifter to complete its transition, again causing to bind.

 

[Dustin Jackson]

@SiWilli You are having a lifter failure for sure. I just went through this. Stop running the engine and being to take it apart so you can examine the extent of the damage and then form a remediation plan based on your findings. I had a similar situation and mine turned out to cost about $2k in parts and tools and about a months worth of weekends.

Here is my initial post outlining my troubleshooting and diagnostic process:

Guys I need help figuring out this engine rattle

Hey guys I think it has come time for my Tahoe for a AFM lifter delete. I think I am having a lifter failure but this sounds different from other videos I've seen. Someone said the pushrod might be out of place causing this sound? What do you think?

www.tahoeyukonforum.com

Here is my second post in which I discuss how to put it all back together:

AFM Delete Double Checking

Hello Guys I am in the process of ordering all the parts I will need in order to complete my AFM delete on my 08 5.3 but I have questions about the oil pump and pressure relief valve situation. Here is a list of the parts I have ordered so far: LS2 Lifter Trays LS2 Chain Dampener (Recommend...

www.tahoeyukonforum.com

If you have any questions let us know

 

[donjetman]

AFM LIFTER FAILURE AND DELETE Utube video:

 

[iamdub]

I vote lifter as well.

I can never remember what year 6.2 didn't have AFM enabled, but had the components in place. Regular lifters can fail, too, though.

I agree- STOP RUNNING IT.

 

[donjetman]

I vote lifter as well.

I can never remember what year 6.2 didn't have AFM enabled, but had the components in place. Regular lifters can fail, too, though.

I agree- STOP RUNNING IT.

Here’s some neat trivia: The 6.2L L92 actually had a first and second design.


The first design, built prior to April 1, 2006 contained AFM components, but were left disconnected from the ECM.


The second design eliminated the AFM components altogether.

Mine was built after that date

 

[iamdub]

Here’s some neat trivia: The 6.2L L92 actually had a first and second design.


The first design, built prior to April 1, 2006 contained AFM components, but were left disconnected from the ECM.


The second design eliminated the AFM components altogether.

Mine was built after that date

Oh, I didn't know it went that far back. So, OP should be good to go if all he has is a bum lifter or something minor in the valvetrain.

@SiWilli, you look into it any further?

 

[SiWilli]

Oh, I didn't know it went that far back. So, OP should be good to go if all he has is a bum lifter or something minor in the valvetrain.

@SiWilli, you look into it any further?

Bum lifter. I stopped driving it immediately and had it towed. Ended up at the dealer for repairs. They’re actually replacing all 8 and the cover on that side. Asked about the gmc satisfaction policy for repairs so I am paying half and will have a bit of a warranty. Picking up tomorrow after work.

 

[swathdiver]

That's definitely a top end sound, lifter or busted valve spring. Good thing you didn't listen to those thieves! Glad to hear you'll have it back manana! Keep us posted!

 

[SiWilli]

Here’s some neat trivia: The 6.2L L92 actually had a first and second design.


The first design, built prior to April 1, 2006 contained AFM components, but were left disconnected from the ECM.


The second design eliminated the AFM components altogether.

Mine was built after that date

And then they brought AFM back in 2010 on the L94. Which is what I have

 

[B-train]

Wowza! That sounded terrible. Glad they got it taken care of for you.

Have you thought of getting the Range AFM disabler that plugs into the OBD2 port? I use one on my 2017 and it is great, no more V4 mode. Fuel economy is still decent as well, no big hit.

I would also recommend being very diligent on your oil changes after these repairs and if you plan to use the AFM. Going by the "oil life" monitor will only cause you headaches down the road due to dirty oil that should've been out sooner.

Unless you strictly do cross country driving (looonnnggg runs, no stop/start) I would recommend 5k or less with an AC Delco filter and full synthetic oil 5w-30.

A helpful tidbit I have used occasionally myself it to run 1/2 quart of ATF in the oil about 100 miles or so before an oil change. The high detergent will wash the motor, clean up gunk in lifters, etc. It helped remedy more than 1 noisy lifter in my tenure as a mechanic.

 

[Blackcar]

Wowza! That sounded terrible. Glad they got it taken care of for you.

Have you thought of getting the Range AFM disabler that plugs into the OBD2 port? I use one on my 2017 and it is great, no more V4 mode. Fuel economy is still decent as well, no big hit.

I would also recommend being very diligent on your oil changes after these repairs and if you plan to use the AFM. Going by the "oil life" monitor will only cause you headaches down the road due to dirty oil that should've been out sooner.

Unless you strictly do cross country driving (looonnnggg runs, no stop/start) I would recommend 5k or less with an AC Delco filter and full synthetic oil 5w-30.

A helpful tidbit I have used occasionally myself it to run 1/2 quart of ATF in the oil about 100 miles or so before an oil change. The high detergent will wash the motor, clean up gunk in lifters, etc. It helped remedy more than 1 noisy lifter in my tenure as a mechanic.

Is there a reason why you don't use 0-20 weight in your vehicle just a question.

 

[B-train]

Sorry for the confusion, I have 2 yukons. My 2008 requires 5w-30 dexos. The new direct injected motors like my 2017 requires 0w-20. However, I still use 5w-30 in that one as well. The new 6.6L direct inject HD engine uses 5w-30 and is basically the same architecture, so that's my reasoning.

 

[donjetman]

I'm having success running 0w-20 oil in my 180k mile 07 Denali w/6.2L L92
https://www.tahoeyukonforum.com/threads/latest-uoa-0w-20-07-6-2l-w-180-k-mi.136491/#post-1711683