Engine advice

[jeff ashworth]

Hi Fellow Tahoe owners, my son has a 07 Tahoe with 5.3 LMG coded motor and it lost compression on #6 cylinder and was wondering if it had that strange lifter oiler or the cylinder oiler and if I heard their was a cam and lifter or cylinder delete system for those.

 

[wsteele]

Hi Fellow Tahoe owners, my son has a 07 Tahoe with 5.3 LMG coded motor and it lost compression on #6 cylinder and was wondering if it had that strange lifter oiler or the cylinder oiler and if I heard their was a cam and lifter or cylinder delete system for those.

Number 6 is one of the four AFM cylinders. A quick way to see if one of the AFM lifters has collapsed is pop the passenger side valve cover off and see if the rockers are all operating properly.

There are a lot of YouTube videos on how to diagnose (and fix) a collapsed AFM lifter. To fix a collapsed AFM lifter, at a minimum you are going to have to pull a head. Most would recommend doing a full AFM delete at that point (new lifters, new cam, a few others things while you are there). Kits can be bought from a number of sources. A simple AFM delete in your ECM software is also part of the process.

A number of very competent members here have been through it and will hopefully chime in.

 

[iamdub]

Hi Fellow Tahoe owners, my son has a 07 Tahoe with 5.3 LMG coded motor and it lost compression on #6 cylinder and was wondering if it had that strange lifter oiler or the cylinder oiler and if I heard their was a cam and lifter or cylinder delete system for those.

As @wsteele said, pop off that passenger side rocker cover and look for a loose rocker on the #6 cylinder. It's quite possible that an AFM lifter has collapsed. There's a trick to unstick the lifter without pulling the cylinder head here:

I'd disable AFM (Here: https://lt1swap.com/afm_delete.htm), unstick the lifter and hopefully it'll be okay for a long while. If not, you're gonna have to do an AFM delete which is replacing all the mechanical components of the system with the non-AFM variants. At least you'll already have it turned off in the PCM tune.

 

[ukrkoz]

OK, I got truck back.
Per mechanic, cyl 6 head had hair crack in it and he replaced it. The head. Engine runs very well.
Thanks to all who posted here.

 

[Bill 1960]

Thank you for posting the rest of the story.

 

[kbuskill]

Thank you for posting the rest of the story.

 

[ukrkoz]

It's done.
Bank 2 new head, new lifters, replaced oil pump and rebuilt transmission. All I have left is small stuff - LF TPMS, rear rotors and detail inside.
Moral to the story - do not buy "mechanical" auction car. Unless you DIY repairs.