2012 Yukon 6.2 Engine Noise

[12XLYukon]

Hi all, I just recently bought a 2012 Yukon XL Denali with the 6.2. It has developed a noise that I can’t identify. It has 214k on the miles.
Noise is coming from driver side and can be heard from under the hood and in the wheel well.
Louder on cold start but still present after driving.
No codes and runs smooth
Oil pressure when idling is 20 at operating temp and 42 when cold started.
Checked the exhaust manifold bolts and all are there except one on passenger side.

 

[Geotrash]

Hi all, I just recently bought a 2012 Yukon XL Denali with the 6.2. It has developed a noise that I can’t identify. It has 214k on the miles.
Noise is coming from driver side and can be heard from under the hood and in the wheel well.
Louder on cold start but still present after driving.
No codes and runs smooth
Oil pressure when idling is 20 at operating temp and 42 when cold started.
Checked the exhaust manifold bolts and all are there except one on passenger side.

Classic lifter failure sound that may not actually be a lifter. Any misfire codes happening to go with it?

It's hard to say for 100% certain because it's in the shadow, but it looks like you may also have a missing exhaust manifold bolt at the rear of the manifold on the drivers side. That can also sound just like a failed lifter - especially if it gets less pronounced as the engine warms. You can get a mechanic's stethoscope from the local auto parts store and see if you can trace it back to that missing stud.

If not, then failed lifter would be my next item to investigate.

 

[donjetman]

What @Geotrash said, definitely valve train related.
and/or
broken valve spring, bent push rod, failed rocker arm trunion.

 

[solli5pack]

Start it with the belt off and see if the noise is still there. That way you can eliminate or isolate accessories as a cause. Sounds like lifter noise to me though...

 

[j91z28d1]

200k is a good run for afm if it's still active.

definitely sounds valve to me.. pull the cover and look for a. loose. rocker?

 

[12XLYukon]

200k is a good run for afm if it's still active.

definitely sounds valve to me.. pull the cover and look for a. loose. rocker?

Classic lifter failure sound that may not actually be a lifter. Any misfire codes happening to go with it?

It's hard to say for 100% certain because it's in the shadow, but it looks like you may also have a missing exhaust manifold bolt at the rear of the manifold on the drivers side. That can also sound just like a failed lifter - especially if it gets less pronounced as the engine warms. You can get a mechanic's stethoscope from the local auto parts store and see if you can trace it back to that missing stud.

If not, then failed lifter would be my next item to investigate.

Classic lifter failure sound that may not actually be a lifter. Any misfire codes happening to go with it?

It's hard to say for 100% certain because it's in the shadow, but it looks like you may also have a missing exhaust manifold bolt at the rear of the manifold on the drivers side. That can also sound just like a failed lifter - especially if it gets less pronounced as the engine warms. You can get a mechanic's stethoscope from the local auto parts store and see if you can trace it back to that missing stud.

If not, then failed lifter would be my next item to investigate.

No misfires codes. Engines seems to run smooth.

 

[Doubeleive]

take a sample of the existing oil to send to blackstone labs and then change the oil with some snake oil additive, drive it a hundred miles, repeat.
then just add regular oil and see if it clears it up and see what the blackstone labs results are.
blackstone labs charges around $35 and gives you a "healthy or unhealthy" synopsis of what is in the oil, like metal, etc.
could just be something "sticky" and if it is more serious then at least you gave it a shot first without high cost.

 

[B-train]

Agreed with above. It definitely sounds valve train to me. You could try ATF, Marvel Mystery oil, or Sea Foam as an addive to the oil to see it it helps unstick the lifter. Sometimes you can get lucky if they have a carbon buildup that the detergents can dissolve. If it clears up, then drop the oil, out in New and drive for 1000 miles. Drop again because it will most likely be quite dark if there is a lot of carbon buildup inside the motor.

Tennessee tune-up: pour in 1 of the 3 items mentioned (max 1/2 to 1 quart). Let idle until warm. Drive it like you stole it......works most of the time on conventional lifters. Not sure about AFM lifters, but it's worth a shot.

 

[j91z28d1]

best to pull a valve cover and inspect first incase it's a rocker trunnion or valve spring. go out and race it around with those might cause more issues


if you're not in a position to pull a cover and next stop is the shop for a new engine, then yeah, try it all haha

 

[12XLYukon]

best to pull a valve cover and inspect first incase it's a rocker trunnion or valve spring. go out and race it around with those might cause more issues


if you're not in a position to pull a cover and next stop is the shop for a new engine, then yeah, try it all haha

What should I look for once I get the valve cover off?