2012 Yukon XL Denali 6.2L Cam Swap Thread

[Geotrash]

So I am equal parts: 1/would totally buy a brand new XL Denali if they were available nearby right now and weren’t experiencing teething pains, 2/putting a brand new engine in this one, and 3/installing just one more cam and hoping for the best.

This isn’t about pennypinching… We make plenty of money to buy a brand new truck, but I genuinely believed I would be able to extend the life of this one indefinitely by getting rid of the AFM system. Had I had any clue the probable implications of what I was about to do, I would have just had AFM tuned out and moved on.

 

[wsteele]

So I am equal parts: 1/would totally buy a brand new XL Denali if they were available nearby right now and weren’t experiencing teething pains, 2/putting a brand new engine in this one, and 3/installing just one more cam and hoping for the best.

This isn’t about pennypinching… We make plenty of money to buy a brand new truck, but I genuinely believed I would be able to extend the life of this one indefinitely by getting rid of the AFM system. Had I had any clue the probable implications of what I was about to do, I would have just had AFM tuned out and moved on.

I think you are nearly there. Just put the good stuff back into the top end and you almost certainly will be there. You know so much about how to optimize this very rig, don’t give up in the 9th inning!

 

[Geotrash]

I think you are nearly there. Just put the good stuff back into the top end and you almost certainly will be there. You know so much about how to optimize this very rig, don’t give up in the 9th inning!

Thanks for the encouragement, Bill. Third time's a charm, I hope. But honestly, my main worry is the potential for damage to the main bearings. They're next in line after the lifter oil galleys in the oil circuit flow. Worst case, I'll drop a new engine in it. Still way cheaper than a new rig and this one is cherry in every other way.

 

[wsteele]

Thanks for the encouragement, Bill. Third time's a charm, I hope. But honestly, my main worry is the potential for damage to the main bearings. They're next in line after the lifter oil galleys in the oil circuit flow. Worst case, I'll drop a new engine in it. Still way cheaper than a new rig and this one is cherry in every other way.

I understand the concern on the mains. Not sure with these production engines if this is considered bad practice or not, but when I was racing, if we had some doubts about the lower end, we would pop the caps off and look for scuffs and scratches on the bearings. If everything looked OK, we just popped them back on and away we went. Of course, we were rebuilding the whole kit and caboodle after each season anyway, so maybe a bad analog.

I think with oil analysis and maybe cutting the filters down with each change, you will likely know what is going on pretty quickly.

I totally agree with sticking with it, regardless if it ends up needing a replacement engine down the road. My truck is in similar shape as yours overall and I literally have looked and looked for something that would fit my needs better and I am convinced they aren't out there. The last thing I looked at was a brand new Land Cruiser, fell in love and got all excited when I found the exact colors I wanted at a local dealer. After driving it, and I went down the checklist of all the things I really like about my Yukon and how it compared to the LC and the Land Cruiser came up short, with only it's off road skills beating the Yukon. Nope. I will just keep fixing it. The really positive thing is all my friends think I have become an eccentric about my truck...

 

[wsteele]

Thinking about it some more, I think your fears of debris making it to the big bearings are probably unfounded.

On the pressure side, I can’t think of a way the loose metal finds its way into the circuit.

If the metal is small enough to stay suspended, I could see it getting pulled up through the return and into the pump, but unless the filter bypasses, can’t see how it ever gets back into the pressure side of the circuit again.

 

[Foggy]

Put it back together with right parts.. You prob have this down to science now...
Change your oil several time in very short intervals... Use cheap walmart oil if you want.
Use good filters though.. If nothing else, it will run very well in the short term and
you can decide then if you want to trade it off for new...
Keep on going !!!! You've found your smoking gun

 

[Geotrash]

Thinking about it some more, I think your fears of debris making it to the big bearings are probably unfounded.

On the pressure side, I can’t think of a way the loose metal finds its way into the circuit.

If the metal is small enough to stay suspended, I could see it getting pulled up through the return and into the pump, but unless the filter bypasses, can’t see how it ever gets back into the pressure side of the circuit again.

I agree with you on the capabilities of these trucks being unmatched in the industry today. The new ones are much more complex in both mechanicals and electronics (delicate), and no other manufacturer offers such a wide range of capabilities in the same truck. It's a refined limo, family hauler, trailer puller and off-roader with very few compromises.

I'm not so much worried about the fragments once they get to the pan. Yes, it could come through the screen on the pickup tube and muck with the oil pump, but I think that's low risk. I'm more worried about where the pieces went as they were breaking away from the lifters before they made it to the pan. The oil flow in an LS engine has it going through the oil galleys to the remaining lifters and main bearings before making it to the pan.

 

[Geotrash]

Put it back together with right parts.. You prob have this down to science now...
Change your oil several time in very short intervals... Use cheap walmart oil if you want.
Use good filters though.. If nothing else, it will run very well in the short term and
you can decide then if you want to trade it off for new...
Keep on going !!!! You've found your smoking gun

Good advice. This is the approach I'll take. Fingers crossed.

 

[wsteele]

I agree with you on the capabilities of these trucks being unmatched in the industry today. The new ones are much more complex in both mechanicals and electronics (delicate), and no other manufacturer offers such a wide range of capabilities in the same truck. It's a refined limo, family hauler, trailer puller and off-roader with very few compromises.

I'm not so much worried about the fragments once they get to the pan. Yes, it could come through the screen on the pickup tube and muck with the oil pump, but I think that's low risk. I'm more worried about where the pieces went as they were breaking away from the lifters before they made it to the pan. The oil flow in an LS engine has it going through the oil galleys to the remaining lifters and main bearings before making it to the pan.

View attachment 350240

I understand what you are saying, but from what I can tell the only damage you have is to the lifter rollers and cam lobes. Any oil carrying the debris from that area isn’t getting back into the pressure circuit going downstream.

If there were internal damage to a lifter, then maybe that might happen, but that doesn’t look like your situation. At least I hope I am right about that.

 

[Geotrash]

I understand what you are saying, but from what I can tell the only damage you have is to the lifter rollers and cam lobes. Any oil carrying the debris from that area isn’t getting back into the pressure circuit going downstream.

If there were internal damage to a lifter, then maybe that might happen, but that doesn’t look like your situation. At least I hope I am right about that.

I think that's right, that roller and cam lobe fragments should stay out of the flow circuit and drop directly into the pan. Gonna do 500-1000 mile oil changes for a few months and hope for the best. Ordered up a bunch of Wix filters and gonna hit Walmart to buy a bunch of oil.