I got me a Tahoe!

[Nutro]

Update! So I got the pass side head off. As suspected, the intake lifter on #4 spun in its lifter tray and was loose. The lifter roller has some pitting but from the angle I can see the cam lobe, it looks mint. All the lobes actually look pretty good on that side.

Question: Why does the top of the piston on that cyl look so pristine and brand new? All the cylinder walls look amazing for 150K but that piston top looks perfectly clean. I will probably just replace all 4 AFM lifters on that side and have the AFM tuned out in the tune and see how she does. Oh and I dropped a shallow socket down into the exhaust manifold so I'll be pulling the y-pipe if I can get under it and the bolts come loose. Yay

 

[j91z28d1]

huh the lifter spun and didn't kill tear everything up. I didn't think that would be possible.

no clue on the clean piston. the pic it looks brand new. that's wild.

 

[Tonyrodz]

Are the headgaskets leaking at all? The coolant will clean the tops of the pistons after awhile.

 

[Fless]

Are the headgaskets leaking at all? The coolant will clean the tops of the pistons after awhile.

^^ This is a distinct possibility, steam cleaning. Look at your head gasket to see if you can tell if coolant was migrating to the combustion chamber.

 

[Nutro]

I'm guessing since that cyl wasn't firing, it was just getting dowsed with fuel and thats why its so clean. I think at this point I will just do a full cam swap and AFM delete. I just need to find a good cam that might be slightly bigger/better than the stock one but I don't want any crazy lope or anything.

 

[mattbta]

I also dropped a socket down the y-pipe. Fortunately used a tool like below to snag it without pulling any more of the exhaust.

https://a.co/d/4dl4swy