2011 Denali Needs New Engine

[matthicks2010]

Hey everyone, Ive done some research but am hoping for some input from yall.

My 2011 Denali is now getting a new engine due to a valve seat failure.

The truck has right below 160,000 miles and a valve seat failed causing the valve to stay open which then the piston impacted it. There was no knocking or anything else that would lead me to believe there was a failure happening. Literally happened as I was starting the truck, no CEL or anything else.

Is this a common failure with the L94? I have been trying to find out but I cannot find anything on it really.

 

[Hi-psi]

My uncle literally just had the exact thing happen to his '09 about two weeks ago. He has right around 170k on his. We're currently looking for a good deal on a longblock to swap in. His hit hard enough to bend the pushrod and crack the piston.

My experience is it can sometimes (not always) be caused by either overrevving the engine, or a temperature related issue. If the engine was ever over heated, if it didn't have a sufficient amount of antifreeze in a cold environment, was run hard/hot and then not allowed adequate time to cool down before being shut off.

These things have aluminum heads, the valve seats are not. Aluminum will expand/contract quicker, so if a situation presented itself regularly that caused the head to heat up or cool down rapidly at a different rate than the seat, you could have a situation where little by little the seat might work it's way loose.