Swaping my 07 avy 5.3 engine for a better year ?

Jaime ranberg · Jan 25, 2022

So I'm new to this avalanche thing and I love my 07 so much,that I'm willing to buy a new engine in hopes that it'll last longer. I'm not a mechanic I'm very blonde,But I do know my year of truck has the 4 cylinder shut down and mine are now misfiring! And causing minut issues but don't wanna go without ! So my question is what year could I swap it with and do I have to replace the tranny as well? Any tip will help!

Vaeagleav · Jan 25, 2022

First welcome to the website.
Why go so extreme with fixing your AV? You may be focusing too much on the problems section on this and other websites. You should try and balance the negativity with looking at the threads about long mileage owners and those with multiple AVs as well as all the optimistic posts about owners wanting a third generation AV to be made.
You didn't say whether you are the original owner of your AV or if you bought it used. If you don't know the history of the AV you may get piece of mind by having a thorough tune-up including all fluid changes, lubrication and inspection. During that ask the mechanic to look for worn parts and loose electrical connections etc.
There are several preventative things you can consider before you let things get worse, get the updated valve cover and consider a device to eliminate the AFM through a tuner or device such as one by Range Technologies. Both discussed in other threads about the 4 cylinder mode.

07AVSS · Jan 25, 2022

Any decent 5.3 is just fine. Plenty of them out there with reasonable miles etc.
Get a Range module and plug it in to defeat the AFM. Problem solved. This from
a guy who pulled and rebuilt my engine at 260K for the same reason. If I had disabled
the AFM on day one, the engine would still be running..

ygmn · Jan 26, 2022

OR just turn off your AFM with a programmer or install a complete delete kit.

Many many options... start cheap work your way deep into your wallet later.
ps welcome to the club

BainMan · Jan 26, 2022

Jaime, if you're already getting misfires related to cylinders with AFM lifters it may be too late for just an AFM disabler (software). Start with diagnostics like the spark plugs, wires, coil packs etc... But if it is lifter trouble, as mentioned above, I would look into a true AFM delete kit. This would include (at least) new lifters, camshaft, valley cover, head gaskets and a tune. This will be much cheaper than a new engine and will eliminate any AFM issues, as there would be no AFM/DOD. You could even choose to get a performance boost by selecting the proper camshaft if you're into that sort of thing.

Do you have a local speed shop? The price might be a little higher, but they will almost certainly have extensive experience with AFM/DOD delete's on these LS series motors. Get a few quotes though, and compare to the advice and price the speed shop is offering.

But from the little information provided (misfires), I would not jump straight to motor swap.