2010 yukon delali, what causes lifter failure?

[steve34459]

2 times in 15 months and the truck is making a loud rattle/knock sound hot and cold. First time no SES, gets repaired by chevy dealer,lifter and camshaft. 15 months later same knock is back and SES turns on with #6 cylinder misfire. Based on the video i made, does it sound like it is a lifer and possibly camshaft problem, again? Also, What causes lifter failure? engine oil, gasoline, etc? Thank you!

 

[kbuskill]

The AFM is prone to failure... the constant locking and unlocking of the AFM lifters eventually causes them to break. If you had turned off the AFM after having the parts replaced you may not be having this issue now.

 

[steve34459]

The AFM is prone to failure... the constant locking and unlocking of the AFM lifters eventually causes them to break. If you had turned off the AFM after having the parts replaced you may not be having this issue now.

By any chance do you know if anything else such as engine oil type/viscosity, gasoline brand/ocatane affects the life of the lifters? Or is it due to the quality of the lifters that isn't on par with the AFM?

 

[iamdub]

By any chance do you know if anything else such as engine oil type/viscosity, gasoline brand/ocatane affects the life of the lifters? Or is it due to the quality of the lifters that isn't on par with the AFM?

Engine oil type, quality and cleanliness, as well as overall engine cleanliness most certainly play a role in the AFM system. With lifters that have to pump up and bleed down and the addition of extra electronic solenoid valves in the oil flow circuit, oil cleanliness and viscosity is very important. Gasoline brand and octane level don't really have any affect. Really crappy gasoline may introduce deposits in the combustion chambers that may end up in the oil system eventually, but that's about as far-fetched as it can get. It's not so much as the quality of the lifters not being on-par with the AFM since the AFM cylinders are the ones that have the unique aforementioned lifters that pump up and bleed down. I believe the failures are because it's extra parts that can and will wear and fail being used in such a critical and maybe even sensitive system. There's just too much going on with the engine's valve train that making the lifters do fancy tricks is too risky.