2015 Silverado 5.3 Engine Rebuild

rab356 · January 6, 2022

I have looked through the conversations on this site but didn't find anything specific YET on my question so I thought I would ask the group and hopefully someone here would be able to provide some discussion on this topic. I have a 2015 I just picked up this last summer, it is a High Country with the 5.3 and now has 140,000 Miles on the odometer. There are a few ticky tacky issues but overall the truck is in excellent condition, interior, exterior etc...... I currently don't see any issues in the drivetrain, the engine runs fine doesn't burn oil or smoke, I just picked up a Diablo Trinity 2 Tuner waiting for it in the mail. I have noticed a vibration in the trans, more of a "cavitation" feel when driving around 40MPH and just coast without load. Don't think this is a huge issue yet. When I had the truck inspected by a Mechanic, the only thing at some point I need to address is the rear main seal is leaking a little bit. My question, at some point I want to address the high mileage and want to know what is the best route to go. Take it in and have it rebuilt? Buy a crate Motor to replace it? Sell the truck and buy a new one? I would like to consider upgrades like adding more power through adding a super charger etc....but would rather not have to replace the tranny/transfer case, so not looking to make it a 1000HP. I am really looking to figure out what my options are so I can start saving for it and planning it. Is it even worth it to rebuild the 5.3 with some upgrades? Would I need to do a lot more if I decided to drop in a 6.0/6.2? If it were your truck what would you do?

shakenfake · January 6, 2022

140,000 miles is not high mileage lol

Sell the truck and buy a new one is my thought. If you aren't attached to it then there is no point in putting a new engine in and then paying more when everything else starts going bad. Just my $.02

There is not a lot more it takes to drop in a 6.2 it is pretty easy just fyi

Saying everything though. I personally love the 14-18 body styles and interiors. That will probably be my next and final truck purchase. I would absolutely shove a 6.2 in there and let it rip day and night. Then again though I am the master at owning money pits so that is probably what it would come to. Just depends on if you really really like the truck or not.

rab356 · January 6, 2022

1 hour ago, shakenfake said:

140,000 miles is not high mileage lol

Sell the truck and buy a new one is my thought. If you aren't attached to it then there is no point in putting a new engine in and then paying more when everything else starts going bad. Just my $.02

There is not a lot more it takes to drop in a 6.2 it is pretty easy just fyi

Saying everything though. I personally love the 14-18 body styles and interiors. That will probably be my next and final truck purchase. I would absolutely shove a 6.2 in there and let it rip day and night. Then again though I am the master at owning money pits so that is probably what it would come to. Just depends on if you really really like the truck or not.

Yep, I realize that 140,000 isn't considered high mileage anymore, but that is pretty much the point of this discussion, I don't want to be in a position where I have a truck that is in need of an engine and not yet have a plan or an idea of what I am going to do. I want to have a plan and be ready for when that day comes or when I choose. On the 6.2 swap, is that something that I can just go buy a complete 6.2 and drop in, or is that a 6.2, computer, tranny etc.....?

I just got the truck and so far of all the GMs that I have owned it is by far the one I like the most and am not looking to sell it right now. I am looking for later when it comes time to do the engine. I also like this body style, not really impressed with the looks of anything past 2018 either, certainly not for the money and I think that given this will be paid off in a few years, it will be more cost effective to start replacing other stuff, really the truck is in excellent condition, based on looking at it, you wouldn't think it has 140,000 miles on it, and that goes for most of the truck.

shakenfake · January 6, 2022

6.2 swap should just be the engine and a tune.

If your truck has AFM parts still inside of it then it is a ticking time bomb though. AFM could fail at any point and wipe out your cam etc.

rab356 · January 6, 2022

2 minutes ago, shakenfake said:

6.2 swap should just be the engine and a tune.

If your truck has AFM parts still inside of it then it is a ticking time bomb though. AFM could fail at any point and wipe out your cam etc.

It is all stock as far as I know, what parts would you swap out for the AFM? I intend on turning off the AFM once I get the Diablo, but would I still need to replace the parts?

shakenfake · January 6, 2022

Yes you still would have to replace the parts. The parts are what fails even if AFM has been disabled via tuner.

You need a new camshaft and new set of lifters. I think there is something else that I am forgetting but I can't remember. That might be it.

rab356 · January 6, 2022

I bought the truck the end of April last year and only have put on around 5K miles, I work from home and don't put a lot of miles on this right now.

rab356 · January 14, 2022

Anyone know how much approximately, I should be looking at if I do an engine rebuild for the 5.3 and also do the tranny at the same time? I would of course want to give it some upgrades to get rid of the AFM/DOD but not looking to go crazy. Would you rebuild 5.3 or would you look for a crate/used?