5.3 engine trouble

[bklu300]

I have an 07' Envoy Denali with 84000mi and had a knocking sound which seemed to be on the top end closest to the fire wall. I ended up getting it towed to a shop and they said that I need a new engine. They said that they did hear knocking at the bottom and it was most likely trashed, and I should just replace it. The oil is good and have always gotten the 5w 30, in fact I literately just got an oil change last week. Before sending to the shop I did check the oil and saw very fine sparkles. Thinking it could just be push levers and rockers? Someone please advise and help, I have a really hard time justifying $6k on an engine with less than 100k miles.
Thanks
BK

 

[BRomanJr]

I have an 07' Envoy Denali with 84000mi and had a knocking sound which seemed to be on the top end closest to the fire wall. I ended up getting it towed to a shop and they said that I need a new engine. They said that they did hear knocking at the bottom and it was most likely trashed, and I should just replace it. The oil is good and have always gotten the 5w 30, in fact I literately just got an oil change last week. Before sending to the shop I did check the oil and saw very fine sparkles. Thinking it could just be push levers and rockers? Someone please advise and help, I have a really hard time justifying $6k on an engine with less than 100k miles.
Thanks
BK

Welcome to the Forum!

The 2005 and up 5.3 has what was originally known as Displacement on Demand (DOD) some time later they renamed it Active Fuel Management (AFM) either way, my point was that this system deactivates 4 cylinders at times when power demand is low. and the lifters used to do this are known to fail and cause upper noises. The lifters (8 total) essentially "collapse" to deactivate and never goes back to normal operation when commanded. This could be the cause of the noise you hear.

I have read some reports that owners just replace the failed lifter and some that replace all 8 while the engine is open. (top end).

Hopefully you find the problem.

 

[The_Roadie]

Welcome! You might get a second opinion from a shop you should check with first to see if they're even familiar with the DOD issues on those engines. A replacement shouldn't cost $6K unless they're getting a low mileage or crate engine like it's a warranty job. These are the vehicles that extended warranties have been saving people on.

When did your warranty run out? You might also call GM regional HQ for assistance.

 

[Wooluf1952]

Welcome

In case you haven't heard:
http://gmtnation.com/forums/topic/218-welcome-to-gmtnationcom-heres-the-story/