I screwed up. What are my 2020 6.2 replacement options?

[nateg20]

I made some bad decisions and believe I destroyed the 6.2 in my 2020 AT4 with just over 86k miles.   The truck was great, it didn't use/lose any oil, had good power and got ~19 mpg.   It was after midnight.  I was 11.5 hours into a 12 hour drive with the family riding along and saw the finish line.  It told me that I should pull over but I didn’t believe it because the warnings were just instant and it wouldn’t let me see any real data.  Unfortunately I didn't make it.  Lots of smoke from the tail pipes, and sprayed oil all over into the drivers side wheel well.  It still starts but sounds horrible and blows white/blue oil from the tail pipes.  On the side of the road I realized all of these warnings were because it had blown the serpentine belt off for some reason.  Bottom line, I severely overheated the engine.   

 

I sent it to a local shop and am unsure of the exact condition of the engine at this point.  Hope to know more on that this coming week.  I’m pretty confident I’ll need to replace the engine.  No warranty of any kind so I’ll be funding this replacement myself.  IF my existing engine doesn’t have any new external inspection ports or other signs of block damage I believe the most cost effective option is likely to get a GM 19420611 remanufactured engine and have the shop swap it out while hoping that I get most of that $7000 core fee returned.  That core fee seems like a huge gamble at this point. 

 

If the engine has any signs of damage (ie where did all that oil come from?!... maybe the oil cooler/ cooler lines?) I’ve been exploring other options to replace the engine.  The first option that comes to mind is finding another L87 from a salvage yard or from eBay.   This option only seems viable if I’m sure I won’t get the core fee returned as these engines seem to have a premium price tag.  In addition I’ve now got an engine with an unknown history.  Rolling the dice.  

 

A slight improvement from this option may be getting a reman L87 from a vendor other than GM.  This price seems competitive with salvage yard engines with better warranty.  I’m referring to vendors such as spprecision, michiganmotorz, fraserengineco, accurateengines, promarengine, and perhaps jasper.  I have no experience with any of these companies and do not know how long they would take to ship.  Many of them claim to have some in stock.  

 

All of the other options almost certainly require giving HP Performance a fair amount of money to get a tuning package. I’ve always been quite skeptical of the DOD on this engine but it really hasn’t caused me any sort of issue.  It would be nice to be able to build a reliable engine and gain some power but I put a fair amount of miles on this thing and would like to continue to do so.  I’d probably want to go straight to deleting the DOD and would be ok with losing a few mpg in order to gain reliability.  I do not even know what options are available and or feasible. I believe all of the GM 6.2 crate engines with direct injection also have DOD.  So that means I couldn’t go with a GM 19435108 (6.2, no DOD).  The only non DOD gen V engines appear to be the 6.6 cast iron block versions.  Maybe an L8T with a cam?  AKA L8P.   

 

Keeping all of the OEM truck functionality (IE keeping GM Global A happy) with any engine other than the L87 seems like a daunting task for even an experienced tuner which I’m not sure that I’ve got access to.  

 

Sorry for the long message, I sincerely appreciate you reading this and really hope somebody who has read it has some insight that I presently do not.  Thank you again.  To summarize, if your truck tells you to pull off the road you should listen to it.  Don’t be like me.  It seems like a very poor time to damage an L87 engine.  

[Silverado4x4]

Sounds to me what you're describing is you blew an oil cooler line off sprayed oil everywhere and ran the motor dry of oil and blew the motor any remaining oil got pumped into the cylinders and the smoke was coming out the exhaust, either way the motor is done. You say the motor started up but sounds terrible pull the dip stick out and I bet there's no oil on the stick.

Edited August 9, 2025 by Silverado4x4

[johnnyquick]

Buy a 6.2 LT4 off of ebay with the ecu and harness and live life to the fullest https://www.ebay.com/itm/396461660323?_skw=lt4+engine&itmmeta=01K2BRN37CJY2BQY2R195EB9H0&hash=item5c4ef4d8a3:g:ZhkAAeSwvRFn~AZK&itmprp=enc%3AAQAKAAAA0FkggFvd1GGDu0w3yXCmi1ftUSppaFS965GIBBXp7lj9UaDy0eObbVVXkiV1DU6EUG1HlL9zD%2Bbyl9oebvF2RbFX2b4B%2FBLPRUJpRygQBVL3%2Fagt9pEGVZRlmj4Hz2ZkOhI5A2dwTyMET3GsO%2Fgqdo7POIRKDAXVd%2FqmiaRjyS6sD0t%2BT7wxR8ZPqR2JPuCjC6FWKnOdMaTfKUx7lKRj%2F7WLZYOi4L6l4S7VbilETm22YUE76BxErSzSIxYJ%2BrO4Ic5cIBeLyMfCvpxjqU4wIcc%3D|tkp%3ABk9SR-6z1PiSZg

[Joe Drives]

You received 86K trouble free miles. I would go with your option 1 and stay with the same engine new or remanufactured by GM with GM warranty. I'm not sure what GM's engine warranty is now but it used to be the same as a new vehicle 3 years 36,000. 

[asilverblazer]

If it happened to me - and I had the funds.

Run it through a machine shop, bore and stroke it

Cam swap

Clean up the heads and valvetrain

DOD delete

Maybe larger injectors

Maybe long tube headers

Maybe larger intake/throttle body

Dyno tune

 

Reuse all other external components.

 

 

 

 

[Grumpy Bear]

On 8/9/2025 at 1:46 PM, nateg20 said:

I made some bad decisions and believe I destroyed the 6.2........  It was after midnight.  I was 11.5 hours into a 12 hour drive with the family riding along and saw the finish line.  It told me that I should pull over but I didn’t believe it because the warnings were just instant and it wouldn’t let me see any real data.  Unfortunately I didn't make it.    

 

Education is expensive, eh? Bet you don't ignore it twice. 

 

You made almost 100K trouble free miles and I'd bet @Silverado4x4 nailed it. 

[nateg20]

Update:

Water pump was the point of failure.  The oil substance in the wheel well was the dex coolant, which there is none of that left in the overflow anymore.  Engine hasn't really lost any oil, but it smells very burnt.   No signs of water in the oil.  

[Silverado4x4]

3 hours ago, nateg20 said:

Update:

Water pump was the point of failure.  The oil substance in the wheel well was the dex coolant, which there is none of that left in the overflow anymore.  Engine hasn't really lost any oil, but it smells very burnt.   No signs of water in the oil.  

Get the oil change ASAP. She probably got hot I hope who is doing the repairs are doing a pressure test to check for any leaks around the head gaskets and intake manifold. The smell of burnt oil is concerning but hard to diagnose over what was said here without being there. If you still have smoke coming out the tailpipe after repairs that will lead to a blown head gasket or worse warped cylinder heads from over heating as coolant is getting into the combustion chambers and that is the smoke your were seeing when you had the issue from the start. 

Edited August 12, 2025 by Silverado4x4

[Bikerjon]

9 hours ago, nateg20 said:

Update:

Water pump was the point of failure.  The oil substance in the wheel well was the dex coolant, which there is none of that left in the overflow anymore.  Engine hasn't really lost any oil, but it smells very burnt.   No signs of water in the oil.  

Good luck. Hopefully the water pump and an oil change takes care of it.

[davidr83]

Have them check the cap for the overflow and the radiator for an oil cooler leak. Similar scenario happened to my 6.2 but i caught it before an overheated situation burned up my engine.

 

Edit: if your oil level was infact full, the radiator check may not be necessary.

Edited August 13, 2025 by davidr83

[Coastie05]

Status update???

[taze]

I really hope he went L8P so he can tell me about the experience. 

[Black02Silverado]

If it did overheat, not sure of the damage, might be worth having it inspected. If not a new engine is way cheaper than a new truck since you already know what you have.  

 

I hope you have serviced the rest of it ie, transmission fluid change at least and transfer case and diff fluid changes.