Radiator that is going bad? That's not good. Is your radiator clogged or leaking? My Denali started to run warm once...Found the radiator and condenser had a bunch of bugs and debris in the fins. I forced the little dead things out with water pressure from the garden hose (from the fan side) and haven't had a problem since. I am not sure if the #7 cylinder demise is on par with your 07...not sure when GM worked that issue out. I am sure the experts will chime in.

With temps above normal, Computer is not going to allow your engine to run very well. You have to fix all the mechanical stuff first. IMO

 

They didn't. It still exists.

To the OP: who did the tune. It really sounds like it ran lean and popped #7. Is it possible a 5.3 tune was loaded?

You need to boroscope that cylinder.

 

pull spark plug and do a compression test on that cylinder. or scope it..

I would put it all back if you could. why did you bore the TB? do you have a stock one to put in it?

 

Sounds like the top ringland is lifted, bad tune up. Ran lean and had detonation. Thats what is allowing the oil in the combustion chamber. A compression check will show you real quick what the issue is.

 

Well guys bad news......seems I have a chunk missing out my piston on #7. Go figure. Worse, the cylinder is messed up as well and needs to go to a machine shop for cylinder sleeve if i decide to keep it. What you guys think?

I have been quoted at 3000 bucks labor for complete rebuild including piston, ring set, bearing main and rod as well as a cam and springs etc from Texas Speed.

OR...

Buy 6.2 Shortblock for 2k and throw a cam in and will also be less labor...prolly looking at around same price @ 3k when all said and done. Question is tho , will this bolt up to my 4L70e?? Or will I need to buy a 6L80e...found one on here for 750...question is will an AWD transfer case work on my truck being its 4wd? THanks for the feedback guys!

 

just buy a 6.2 and swap your front cover/flex plate/oil pump install. youd save a lot of money if you are able to install it yourself...

i did mine in 2 days total with only working on it after work and 1 full day of working on it.

 

either buy another L76 or buy you a 6.2L... itll probably be cheaper unless you do some of the work yourself...

and yes it will bolt up to your 4l70e....

 

What kind of flexplate will I need? Cost? And Will I be able to use my same PCM thats on the truck now?

 

use your stock flexplate, and your stock ecm will work.