Camshaft/lifter failure 2012 Yukon Denali

[Rad03]

Hi all,

I recently purchased a 2012 GMC Yukon XL Denali (6.2L) about 9 months ago with currently around 128k miles. The vehicle was running fine until recently when driving home, we hear a "pop", almost sounded like we ran something over (but didn't) and the engine started having some clicking type noises that get louder with acceleration.

I took a quick code from the vehicle and it reporting misfires in cylinder 1. I took it in to the shop for inspection and they diagnosed the issue as camshaft/lifter failure. They are recommending a replacement engine due to time taken to fix headers is quoted around 20+ hours (same or more than engine replacement). New engine replacement is quoted at $9300 from this shop for everything including two motor mount replacements (which are cracked). I just find it tough to consider a full replacement engine at 130k miles opposed to a camshaft/lifter work as they are recommending.

I am pretty out of my element when it comes to an engine replacement and my previous experience with working on cars involve much smaller projects when needed. Quick searching shows that lifter failure is common on this vehicle if it has AFM (which honestly don't know if it has - assuming so).

Rookie type questions below to help me determine best path to take from others who potentially has had this issue on this engine:
Is there a known way to block the AFM that I should consider having done? If so, does anyone know how much of a difference in gas millage this would be? Has anyone who has had camshaft/lifter work done previously have any issues after fixing?

 

[Mechanic421]

You should find a reputable shop in your area. Have them quote you repair vs replacement engine. I am pretty sure you can do the whole valve train in the truck without removing it. But really to repair your engine it probably needs pulled anyway to do cam bearings, barbell,oil pump and pickup o-ring.

 

[wjburken]

I had a lifter go out and scrub the cam in my 2007 Denali. Was able to replace cam and lifters with engine in the truck. It had 272K so swapping engines was not high in my list. Definitely doable in a weekend if you have the parts on hand.

 

[Rad03]

Thanks, for sure leaning towards fixing the cam and lifters instead of replacing the engine like the shop recommended. Waiting on a quote for just the lifters, cams and engine mounts replaced. Sucks to have such work done at 130k miles

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here for these trucks, and you can trust their judgment and recommendations.

If you are contemplating performing the repairs yourself, you will need a fairly good complement of tools in your possession. Are you well stocked with tools?

 

[1BADI5]

Engine replacement would only be required if enough junk/metal got into the motor to wipe out the cam and main bearings.

Like others have said, if caught early, only the cam and lifters would need replacement. I'd recommend doing the full AFM delete since they will already have the heads and front cover off. No additional labor, but under 1k in parts and never have to worry about it again.

 

[Rad03]

thanks for the feedback!

You're correct, I probably wouldn't have the tools for something like this. I have only attempted smaller projects in the past. This will likely be done in a shop, much to my dread.

AFM delete makes sense, I'll check into this if I just do lifeter/cam work.

In terms of quotes from the shop, there is only a $2k difference between a new engine and fixing the lifters/cams. $9700 for new engine with 6 year warranty/100k miles, or $7500 for cam work. This includes two engine mount replacement and other shop fees. They were explaining to me that there is a improved engine design for these vehicles which solves the original issues with these engines that caused them to fail like this. If the price point is not hugely different, I may consider this.

$7500 does seem high for cam/lifter work and two engine mounts, may see what other shops quote.

 

[wjburken]

thanks for the feedback!

You're correct, I probably wouldn't have the tools for something like this. I have only attempted smaller projects in the past. This will likely be done in a shop, much to my dread.

AFM delete makes sense, I'll check into this if I just do lifeter/cam work.

In terms of quotes from the shop, there is only a $2k difference between a new engine and fixing the lifters/cams. $9700 for new engine with 6 year warranty/100k miles, or $7500 for cam work. This includes two engine mount replacement and other shop fees. They were explaining to me that there is a improved engine design for these vehicles which solves the original issues with these engines that caused them to fail like this. If the price point is not hugely different, I may consider this.

$7500 does seem high for cam/lifter work and two engine mounts, may see what other shops quote.

On my '07, I went with a crate motor at 150K when a lifter exploded and sent shrapnel through out the motor. Came with a 100K parts and labor warranty for $6000. Fast forward to 272K I had another lifter lock up and scrub my cam. After getting quotes I decided to do it myself. I think I had around $2000 in parts and fluids. I had a quote for $3000 labor just to diagnose and an estimate for another $3000 parts and labor if it was just a cam and lifter. I figured the $4000 I would save would more than cover a few tools that I might need to buy. Only tools I ended up needing to get was a 3/8" and 1/4" torque wrench as I already had everything else. My '07 6.2 didn't have AFM so I didn't have to mess with that.

 

[thompsoj22]

thanks for the feedback!

You're correct, I probably wouldn't have the tools for something like this. I have only attempted smaller projects in the past. This will likely be done in a shop, much to my dread.

AFM delete makes sense, I'll check into this if I just do lifeter/cam work.

In terms of quotes from the shop, there is only a $2k difference between a new engine and fixing the lifters/cams. $9700 for new engine with 6 year warranty/100k miles, or $7500 for cam work. This includes two engine mount replacement and other shop fees. They were explaining to me that there is a improved engine design for these vehicles which solves the original issues with these engines that caused them to fail like this. If the price point is not hugely different, I may consider this.

$7500 does seem high for cam/lifter work and two engine mounts, may see what other shops quote.

Also welcome, Just my 02 but a 6 year/100,000 mile parts and labor warranty is no joke and appealing if you have the cash. I unknowingly bought an 08 denali 6.2 that avoided this whole mess. My only requirement for the new engine is that it did not come with the DOD option and they replace the trans convertor all for $10K? hang in there, Is this a GMC dealer that you are doing business with? If you are doing a new engine their warranty exceeds all others in that your warranty could be used at any Chevy/GMC dealer nation wide. Get another quote?

 

[iamdub]

As @1BADI5 said, it can be saved and improved upon if metal didn't destroy the bearings. Since the cam and lifters need to be replaced anyway, you may as well go back with non-AFM parts. Any loss in MPG from not having AFM will be FAR less cost than what you're having to pay now. Unless you do 90% of your driving at 70MPH or below for extended periods, AFM isn't saving you anything. Well, it may be saving you a buck or two in fuel per fill-up, but it's costing you thousands now. Delete. Delete. Delete.

I just finished a delete on my 5.3. I used a mild performance cam, catless headers and bumped up the compression a little. I'm now getting 2-3 MPG MORE at 70 MPH.

Your quickest solution would be to find a good used 6.2 that didn't have AFM and swap it in. Otherwise, you'll have to have yours pulled, opened up and inspected. THEN you'll know if it's worth saving it. Non-AFM Gen IV 6.2 would be the L9H or the L92 (built after April 1, 2006 for the one that didn't have AFM at all- prior to that had AFM components but it wasn't activated in the tuning). You could find another L94 (what you currently have), delete it and swap it in if that's worth it to you.