2007 Yukon Denali...no compression cyl #8

[petethepug]

If it were anything other than a Denali AWD without the AFM from 07, 08, 09 I'd say sell it on. Find the potential shop, dude or whoever who works on your stuff. Verify if it's the head or the cylinder. One of those is much less expensive. It's a good looking rig and yes, stabilitrack lights up when you have cylinder misfire. If stabilitrack was not lit up before the misfire, don't include that in your problem list.

 

[GMperformance03]

Thanks for all the input. The best I could find so far was a shop to put in a used motor for $3,800 installed. It does come with a 60 day warranty. These 6.2 motors are expensive (reman or used).

 

[GMperformance03]

I’m learning more and more about these motors, so please excuse my ignorance. To my knowledge I don’t have AFM leading me to believe a failed lifter or valve is the culprit ( hoping no cylinder or piston damage). If that is the case should I rebuild both heads or only focus on the faulty head if I do decide to keep it?

Also, what are the probabilities of having camshaft damage due to a failed lifter in a non-AFM motor?

 

[swathdiver]

I’m learning more and more about these motors, so please excuse my ignorance. To my knowledge I don’t have AFM leading me to believe a failed lifter or valve is the culprit ( hoping no cylinder or piston damage). If that is the case should I rebuild both heads or only focus on the faulty head if I do decide to keep it?

Also, what are the probabilities of having camshaft damage due to a failed lifter in a non-AFM motor?

If you're even minimally mechanically inclined and can read a manual and use tools you can fix it yourself. Focus on the problem area first, KISS.

Camshafts can get wiped if the lifter guide cracked allowing the lifter to rotate. If the camshaft bearings need replacement, then the motor has to come out. But often they do not need replacing, especially if you still have good oil pressure.

 

[petethepug]

No matter what you're going to have to run a check list down the line for the most to least likely culprit. You call a diagnosis once you've got the facts.

Call the seller from a cell phone he wont associate with you. Don't leave a message and hang up if he doesn't answer. He'll call back out of curiosity. This will save all the usual bs of him (potentially) avoiding your calls if he did a dirty deal. #1 ask him a good place to have it serviced. #2 ask him what his 2nd choice would be. #3 Ask him if he has any info on why #8 has dead air. Ask him if he has any tools you could borrow like a torque wrench or cherry picker to swap the motor. Make him aware you're up shit creek but be nice about it.

Maybe he'll help you out. Maybe he'll lead you to the mechanic that did some work on the truck and you can get some info on the motor or will tell you that you got a dirty deal. Either way, be nice, no matter what. Leave all the doors open in case you find out that he knew the motor was on it's way out. People generally will want to help you out and eventually the truth surfaces if it's different than what you were told.

 

[GMperformance03]

pull the fuel injector power so you don't burn up the catalytic converter as well
and run it as a v7 banger

if you plan to move it
\
it only takes a mile or two to burn it out my experience in another car

What is the best way to do this?

 

[BG1988]

What is the best way to do this?

unplug the power to the fuel injector on the cylinder that is misfiring or have it towed