2024 6.6 gas 28000 engine failure

chris21 · May 14

And crickets... @James McArthur a few of us had questions of genuine curiosity.

The pictures you shared showed dark colored oil and dirt/dust? residue on the mating surfaces of the head where the intake manifold was attached. Those mating surfaces should be clean.

Edited May 14 by chris21

Chuck FB · May 14

1 hour ago, chris21 said:

And crickets... @James McArthur a few of us had questions of genuine curiosity.

The pictures you shared showed dark colored oil and dirt/dust? residue on the mating surfaces of the head where the intake manifold was attached. Those mating surfaces should be clean.

I had not been looking closely enough at that photo posted as it wasn't the point of engine failure, until now when you made that comment on the sealing surfaces of the intake ports looking discolored. I saved the photo so I could zoom it in and while I have no other example used engine photo of this type to compare with to see what the gasket imprint would normally look like, that sure doesn't look right to me either. From how my eyes interpret that, its almost as though its dirt tracking on some of the ports at the top in the center, like the gaskets were not sealing properly due to whatever reason and if someone has been fiddling with this engine prior or its some factory screw up or defect that the intake didn't clamp down properly. I wonder if this engine got dusted and if some cylinders were running lean due to the vacuum leak.

OS RR · May 15

On 4/28/2026 at 9:56 PM, No F-bdy Bs said:

Got a feeling someone is confusing the 6.2 for the 6.6.

Just like everyone seems to do with that "junk GM/FORD designed 10 speed" and the HD's 10spd.

Mostly on facebook... the cesspool of stupid that it is.

asilverblazer · May 15

On 5/14/2026 at 4:15 PM, Chuck FB said:

...its almost as though its dirt tracking on some of the ports at the top in the center...

Looks like how the gaskets are made to me. If it were that lean a check engine light surely would have come up.

Chuck FB · May 15

35 minutes ago, asilverblazer said:

Looks like how the gaskets are made to me. If it were that lean a check engine light surely would have come up.

True, mind you up to a point I assume the system would try to correct and if it wasn't a very high volume leak I imagine it might deal with that ? ( that's a question for someone with experience with these newer systems to answer ). However lets say there was a small amount of dirt getting past, it looks like there is that same type of color dust in the valley area as there is on the upper part of the ports and that narrow band that looks like it crosses over in the middle at the top of a few ports.

Hopefully we hear something at some point from the OP once its all sorted out although he may never be shown or told what the mess really looks like inside the engine.

chris21 · May 16

15 hours ago, asilverblazer said:

Looks like how the gaskets are made to me. If it were that lean a check engine light surely would have come up.

Not sure about the current DI motors, but with the previous generations of 5.3 and 6.0 an intake leak would be audible long before it threw any codes.

Chuck FB · May 16

7 minutes ago, chris21 said:

Not sure about the current DI motors, but with the previous generations of 5.3 and 6.0 an intake leak would be audible long before it threw any codes.

What type of sound was being created from what amounts to a vacuum leak. Exhaust leaks I can see ( I mean hear ! ) but in going back in time to days of the carb or throttle body and if there was a vacuum leak due to lack of clamping force on the intake gaskets, idle speed being increased was one sign but not an actual sound. Now if its an engine with a turbo and on the boost side, that certainly can sound off when under higher boost ( in reference to highway tractors or field tractor issues I have had over the years, rubber bellows splitting or the bellows clamp failing and massive air escaping )

chris21 · May 16

57 minutes ago, Chuck FB said:

What type of sound was being created from what amounts to a vacuum leak. Exhaust leaks I can see ( I mean hear ! ) but in going back in time to days of the carb or throttle body and if there was a vacuum leak due to lack of clamping force on the intake gaskets, idle speed being increased was one sign but not an actual sound. Now if its an engine with a turbo and on the boost side, that certainly can sound off when under higher boost ( in reference to highway tractors or field tractor issues I have had over the years, rubber bellows splitting or the bellows clamp failing and massive air escaping )

Intake leaks can make a whistling sound as they change the flow of air in the intake.

Edited May 16 by chris21

James McArthur · May 17

On 4/27/2026 at 8:46 PM, James McArthur said:

Started as ticking noise 2 days ago, I was afraid it was lifters so parked truck until Monday so I could get it to dealership.

on my way to dealership ticking noise turns to clank clunk awful noise, afraid engine is blown, will find out tomorrow when they check it out. Did I mentioned it’s a 2024 with only 28,800 miles on it? This should not be happening so soon. Anyone else experience this?

James McArthur · May 17

Sorry for the crickets: I’ve been waiting to find out when new long block comes in. It arrived at dealership this past Wednesday and dealer said it should be ready to be picked up next week sometime.

all I can tell you is the lifters started rattling and the next the rod bearings went, dealer has little explanation why a truck with 28000 miles went!! I can tell you the motor has never been worked on and was doing great until it wasn’t, the oil was changed regularly on time as stated before!

newdude · May 18

On 5/16/2026 at 8:14 PM, James McArthur said:

Sorry for the crickets: I’ve been waiting to find out when new long block comes in. It arrived at dealership this past Wednesday and dealer said it should be ready to be picked up next week sometime.

all I can tell you is the lifters started rattling and the next the rod bearings went, dealer has little explanation why a truck with 28000 miles went!! I can tell you the motor has never been worked on and was doing great until it wasn’t, the oil was changed regularly on time as stated before!

Mass production. Things happen. 6.6 and the 5.3 have a lower failure rate than the 6.2 all day long. In the going on 7 years this engine has been out, we've replaced one engine, and it was at 80,000mi and was very neglected as far as service went.

Edited May 18 by newdude

KARNUT · May 18

I was listening to the CarPro radio show Saturday while walking. The caller asked about a new Suburban with the 6.2. He answered the whole 6.2 thing was a little over blown considering the amount produced. Yes it’s high but not wide spread. He’s confident the new ones are fine. I have two V-6 Honda’s currently with high mileage. One is known as an oil user and had an extended warranty sent out to owners. The other is considered bulletproof up to 300k miles and beyond. The (bad) one doesn’t use a drop. The (good) one uses a qt every 4K miles. Not a problem. Just shows luck of the draw comes into play.

newdude · May 18

1 hour ago, KARNUT said:

I was listening to the CarPro radio show Saturday while walking. The caller asked about a new Suburban with the 6.2. He answered the whole 6.2 thing was a little over blown considering the amount produced. Yes it’s high but not wide spread. He’s confident the new ones are fine. I have two V-6 Honda’s currently with high mileage. One is known as an oil user and had an extended warranty sent out to owners. The other is considered bulletproof up to 300k miles and beyond. The (bad) one doesn’t use a drop. The (good) one uses a qt every 4K miles. Not a problem. Just shows luck of the draw comes into play.

Pretty much. Family friend just got a 2026 Sierra Denali with the 6.2. Trouble free so far.

asilverblazer · May 19

On 5/18/2026 at 10:18 AM, KARNUT said:

He’s confident the new ones are fine.

What was done to correct them?

The cynic in me says probably not enough (if anything) considering they're about to be a has been with the next generation coming on line.

KARNUT · May 19

11 minutes ago, asilverblazer said:

What was done to correct them?

The cynic in me says probably not enough (if anything) considering they're about to be a has been with the next generation coming on line.

I was just passing on information from a supposedly knowledgeable source. If I was still buying every two- three years for work. I would probably buy one as long as I could cover it with warranty. I always had spares just in case.