2009 Yukon Denali 6.2 L9H Engine Replacement

[KraftMatic87]

Glad to see you bring this issue to this forum from FB. THESE GUYS REALLY KNOW THEIR SHIT

I’m glad I did too! I had plenty of people on FB telling me to just do an oil change and send it. My instincts said that was bad advice I knew this is something potentially catastrophic and I’d like to minimize my financial pain in getting it resolved

 

[alpha_omega]

My 09 Tahoe with the same L9H as yours made that noise too. Mine ended up being a valve seat coming loose out of the head. The valve seat eventually broke in half and made its way into a piston and destroyed it. I wouldn't be so sure you have a rod nock, but you should get a good diagnosis of it. If your head is doing what mine did, you're looking at 1k or less in repairs. If yours fails like mine did, it's gonna cost an engine. I'll post a video of what mine sounded like before it blew up

100% NOT a rod knock. The frequency is half crankshaft RPM. Valve train for sure.

If it were mine, I’d pull the heads, have them reworked by a competent shop, replace all lifters and get a good look at the cam through the bores. If any damage noted, I’d put a cam motion stage 2 truck cam in it (3-bolt) and call it a day. Actually more like a weekend

x2 on what both of these guys said. From that first set of videos it also sounds like you have a pulley going out. That’s an easy fix that will quiet things down a bit in order for you to better pinpoint the source with a scope.

Id say you’re better off keeping this vehicle and doing the repairs. Oil cooler lines and trans cooler lines are an easy swap and well worth the investment. From the photos it’s not 100% that you have a leak in the pan. The info you’re being fed by the shops could be because you’re going in there with a laundry list of problems, in which case they will gladly agree with you to pocket any extra cash for something you may not even need to replace. That’s not to say that you don’t have a problem internally, because something in there doesn’t sound right, but a rod knock it is not. At least not currently.

 

[KraftMatic87]

x2 on what both of these guys said. From that first set of videos it also sounds like you have a pulley going out. That’s an easy fix that will quiet things down a bit in order for you to better pinpoint the source with a scope.

Id say you’re better off keeping this vehicle and doing the repairs. Oil cooler lines and trans cooler lines are an easy swap and well worth the investment. From the photos it’s not 100% that you have a leak in the pan. The info you’re being fed by the shops could be because you’re going in there with a laundry list of problems, in which case they will gladly agree with you to pocket any extra cash for something you may not even need to replace. That’s not to say that you don’t have a problem internally, because something in there doesn’t sound right, but a rod knock it is not. At least not currently.

I agree with you and I would gladly get this fixed. My problem like you said is that I keep going to mechanics and they all telling me I need to spend $8k - $10k for an engine replacement. I’ve paid diagnostic fees 3-4 times and all I get is “it’s making a knocking noise”. NO SHIT SHERLOCK! I’m going to get this thing to an engine shop next week instead of sending it to a general mechanic. I want to get to the bottom of this and have peace of mind before I start trying to drive this truck up to the mountains with my family on the weekends.

 

[Geotrash]

I agree with you and I would gladly get this fixed. My problem like you said is that I keep going to mechanics and they all telling me I need to spend $8k - $10k for an engine replacement. I’ve paid diagnostic fees 3-4 times and all I get is “it’s making a knocking noise”. NO SHIT SHERLOCK! I’m going to get this thing to an engine shop next week instead of sending it to a general mechanic. I want to get to the bottom of this and have peace of mind before I start trying to drive this truck up to the mountains with my family on the weekends.

It boggles my mind how any mechanic worth their salt standing next to this engine while it’s running, would conclude that it’s a rod knock.

 

[j91z28d1]

if you could just find someone local to pull the heads and drop them off at a machine shop for you.

more of a small shop or a performance based shop maybe. big name chains just sling parts and don't wanna deal with come backs. swapping an engine is easier, and faster. taking up less shop space as it takes a while to get work from a machine shop these days, these shops and employees only make money when things are moving. it's just the price of engines are crazy now. I don't know how they can justify these prices for stuff the make millions of.


few years back i had some valve guides replaced in a set of aftermarket heads. came to like 800$, I'm like man i paid 950$ for these brand new lol. those days are long gone thou.

 

[KraftMatic87]

It boggles my mind how any mechanic worth their salt standing next to this engine while it’s running, would conclude that it’s a rod knock.

Yeah the fact that two shops said Rod knock and another said lifter failure really didn’t give me any info how to fix other than I need a new engine. I’m taking the truck to Colorado Performance & Repair in Northglenn next week if I don’t hear back from Tolman Performance in Colorado Springs. I’m hoping they can get me an answer and a repair plan to get this truck back on the road so I’m not paranoid about dropping a valve at any moment!

Colorado Performance Northglenn | Expert Auto Repair Services

Colorado Performance Northglenn - Expert automotive repair and performance services. Visit us in Northglenn today!

www.colorado-performance.com

 

[mikeyss]

This is what happened to my valve seat. It probably came loose from the head, and was clacking against the valve for who knows how long. Mine let loose on the way from the parking lot moving to the inside of the shop. I was going to do a cam/lifter swap and put on ARH headers ONLY that day until this happened, haha. The reason I was planning on a cam/lifted away was because of this noise! I thought it was a bad lifter, but nope...

That's what was left after the seat broke. Half of it got wedged in the intake valve, the other half took a trip down to visit the piston.

 

[KraftMatic87]

OMG

 

[KraftMatic87]

View attachment 402078This is what happened to my valve seat. It probably came loose from the head, and was clacking against the valve for who knows how long. Mine let loose on the way from the parking lot moving to the inside of the shop. I was going to do a cam/lifter swap and put on ARH headers ONLY that day until this happened, haha. The reason I was planning on a cam/lifted away was because of this noise! I thought it was a bad lifter, but nope...
View attachment 402079That's what was left after the seat broke. Half of it got wedged in the intake valve, the other half took a trip down to visit the piston.
View attachment 402080View attachment 402081View attachment 402082

Holy sh*t that’s a lot of carnage. Definitely getting a tow where ever it needs to go. Ugh I’m scared lol this really sucks. I’ve lost so much sleep over this the past few weeks I am dying for someone trustworthy to take this job on for me bc I’m not capable of properly diagnosing and fixing this myself. I do have a really bad feeling with it and just want answers. If someone can just properly diagnose I’d at least know the extent of the damage but yeah I am definitely afraid to drive it anywhere at all until it gets looked at again.

 

[mikeyss]

I agree with you, it's better to be safe than sorry. Unfortunately, the only way to know if you are having the same issue as I did, is by having the heads removed and thoroughly inspected.

 

[Geotrash]

I am dying for someone trustworthy to take this job on for me bc I’m not capable of properly diagnosing and fixing this myself.

Are you sure? If you’re not interested in learning, then that’s one thing, but to say you’re not capable is something different. All of us started from zero and over time learned to wrench. Removing the heads is not a particularly difficult job and there are a ton of good videos and guides on how to do it. All of the tools you’d need can be borrowed from your local parts house as well.

I did this job myself with the help of these resources and the good people here. Got stuck in a couple of spots but within a few minutes had my answers.

 

[KraftMatic87]

I agree with you, it's better to be safe than sorry. Unfortunately, the only way to know if you are having the same issue as I did, is by having the heads removed and thoroughly inspected.

I’m definitely willing to go that route to avoid more pain in the future. I’m at 144k miles and have only driven it about 600 miles since I bought it. At this point I don’t think I’ll feel safe until someone pulls the heads and we can have a look inside before it self-destructs.

 

[KraftMatic87]

Are you sure? If you’re not interested in learning, then that’s one thing, but to say you’re not capable is something different. All of us started from zero and over time learned to wrench. Removing the heads is not a particularly difficult job and there are a ton of good videos and guides on how to do it. All of the tools you’d need can be borrowed from your local parts house as well.

I did this job myself with the help of these resources and the good people here. Got stuck in a couple of spots but within a few minutes had my answers.

I could definitely learn how to pull the heads but I’ve never done that before. The most major repairs I’ve ever done were changing rotors and brake pads on my Volvo V50 and my Highlander. I just would be at a complete loss how to fix whatever is going wrong. I’ve done a ton of research trying to just diagnose this noise on my own and while I think I’m smart I’m coming to the conclusion that I’m a little out of my depth when it comes to tearing down and rebuilding a motor. I’ll try seeing if pulling the heads is something I can reasonably do on my own but my fear is that I’ll then need a shops help anyway to help me fix this if I find something that is going to require more involved repairs.

 

[wjburken]

I could definitely learn how to pull the heads but I’ve never done that before.

I had that problem once. Then I did it. Take your time and pay attention to how things come apart and you can do it.

Some great resources here to help along the way.

 

[Fless]

If it needs head / valve work, check out Jim's Automotive Machine Shop up by Greeley (near Gill). No direct experience with them, but they seem to do excellent work.

Jim's Automotive Machine Shop, Inc.

Automotive Machine Shop located near Greeley, Colorado. Specializing in light industrial and agricultural engine machine work.

www.jimsmachineinc.com

JAMSI Online - Automotive Engine Parts

JAMSI is a trusted source of automotive engine parts. With over 35 years of experience in automotive machining, you will not find a more trustworthy and reliable source of parts. Visit www.jamsionline.com to shop today.

jamsionline.com

https://www.youtube.com/channel/UCN0rAGKAOHjPLCVwvKPLX9w

 

[Tonyrodz]

Hard to find a trustworthy mechanic today. Lots of greedy parts swappers out there tho.

 

[petethepug]

First off, it’s a one year only Denali with No AFM & runs e85. It’s a 300k+ drivetrain.

2nd, it’s time for it’s 2nd major service. What you do to it now will extend the service life as well as give a one time view of its normally inaccessible internal health.

3rd, you can work a lot of other maintenance related jobs into a potential tear down for little or no labor cost.

You’re moving in the right direction. My Indi has tackled at least three major do-overs I would of been stuck with on our 08 YXL Denali & 09 Esky over the span of a decade… steering rack, trans rebuild and fuel pump. All those jobs need a lift to save time & energy.

With two kiddos and the Mrs & I both working, my hindsight was 20/20 fortunately. The jobs aren’t bad to do. The problem lies when things go sideways. I rebuilt the same motor 3x @ 19 because a reman factory gave me 3 bad short blocks. Live & learn

Happy Father’s Day!

 

[KraftMatic87]

First off, it’s a one year only Denali with No AFM & runs e85. It’s a 300k+ drivetrain.

2nd, it’s time for it’s 2nd major service. What you do to it now will extend the service life as well as give a one time view of its normally inaccessible internal health.

3rd, you can work a lot of other maintenance related jobs into a potential tear down for little or no labor cost.

You’re moving in the right direction. My Indi has tackled at least three major do-overs I would of been stuck with on our 08 YXL Denali & 09 Esky over the span of a decade… steering rack, trans rebuild and fuel pump. All those jobs need a lift to save time & energy.

With two kiddos and the Mrs & I both working, my hindsight was 20/20 fortunately. The jobs aren’t bad to do. The problem lies when things go sideways. I rebuilt the same motor 3x @ 19 because a reman factory gave me 3 bad short blocks. Live & learn

Happy Father’s Day!

I knew it was due for its 150k mile service anyways it just appears that the previous owner had a lot of deferred maintenance that was not mentioned on a pre-purchase inspection from the shop I took it to. Tough lesson to learn but time to move forward. I’m going into this knowing I’m going to do a major tear down and just get this motor back working the way it should. I’m willing to invest the money I need to get it going, it’s just been a tough ride the past few weeks.

Looking forward to the day I can turn the key on this truck and hear a nice clean idle.

Happy Fathers Day to you too!

 

[KraftMatic87]

Did you put the extension in your ear and look for the source of the noise? It sounds exactly like what happened to Mike and if that's the case for you, it's a relatively easy and inexpensive fix compared to overhauling or replacing the entire engine.

Careful with those low dollar estimates, know exactly what you're getting for that.

Do you have a link to a thread about what happened to Mikes truck? If there is one?

 

[Fless]

Do you have a link to a thread about what happened to Mikes truck? If there is one?

I think it's this one: https://www.tahoeyukonforum.com/threads/mikeyss-build-thread.118770/