Well I got me a PPV Tahoe finally (Yay?)

[Nutro]

Well, I bought a 2014 Texas DPS Tahoe with a 150K mile 5.3L yesterday and she's got a P0304 Cyl 4 misfire. I looked on the Carfax and called the last shop that serviced it. They said the trooper brough it in back in Dec of 2022 for a rough idle and P0304 code. They tried a new injector, new plug and new plug wire on that cyl. No change. They tried an upper intake cleaner, nothing. Cleaned the MAF and no change. It idles quietly with no strange ticks or noises.

That mechanic said he told the trooper that it was probably a collapsed AFM lifter so DPS retired it and now I ******* own it (Yay)
I need to get it home and pull the valve cover on that Pass side.

Do I:
Check/inspect the valve spring and if broke, replace it and send it?

Compression test that cylinder?

Yank the heads and AFM/DOD delete it then have it tuned?

If I go ahead with the AFM/DOD delete, I think I read that I can use a NON AFM 6.0L or 6.2L cam? I don't need a lope or anything wild, this will be a daily/kid hauler to the beach on occasion. What cam would y'all suggest?

 

[Marky Dissod]

Well, I bought a 2014 Texas DPS Tahoe with a 150K mile 5.3L yesterday.
She's got a P0304 Cyl 4 misfire. I looked on the Carfax and called the last shop that serviced it.
They said the trooper brought it in back in Dec of 2022 for a rough idle and P0304 code.
They tried a new injector, new plug and new plug wire on that cyl. No change.
They tried an upper intake cleaner, nothing. Cleaned the MAF and no change.
It idles quietly with no strange ticks or noises.

That mechanic said he told the trooper that it was probably a collapsed AFM lifter so DPS retired it
and now I ******* own it (Yay). I need to get it home and pull the valve cover on that Pass side.

Do I:
Check/inspect the valve spring and if broke, replace it and send it?
Compression test that cylinder? Yank the heads and AFM/DOD delete it then have it tuned?

If I go ahead with the AFM/DOD delete, I think I read that I can use a NON AFM 6.0L or 6.2L cam?
I don't need a lope or anything wild, this will be a daily/kid hauler to the beach on occasion.
What cam would y'all suggest?

Might not (only) be the valvespring, might (also) be the lifter and/or the pushrod.

Any non-Engine Half@$$ GM cam, 5.3L, 6.0L, or 6.2L will do - but an aftermarket cam MIGHT be a better value?
If its got 3.08, the other underappreciated bang for the buck would be 3.42 or 3.73, regardless of cam.
3.42 or 3.73 might improve MpG, defraying the cost. Cams NEVER pay for themselves like better axle gears.