I'm the unfortunate owner of a 2021 Trail Boss. It had 41k miles when I bought it used. First time I attempted to tow my 6000lbs trailer (4th day of owning it) the engine managed to blow up on me. Heard from the dealer today that GM is replacing the engine under the power train warranty. My question is, does the engine itself require a break-in before towing with it? I see that the break-in period may relate to the diff, tranny & brakes...and not so much the engine itself. Any thoughts on this? I'm sure I can manage to drive it around for 500 miles before towing, if that's all it takes.
Engine Break-In?
- Thread starter Brad10281
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clstark7
Active member
I have never seen anything in writing regarding this, but it seems like the general rule-of-thumb is 5,000 miles. I hear that's how long you want to wait to change the oil too, for similar reasons. That's what I did. But dang, I have never heard of engine failures that early! I have the 6.2 and am at 42,500 miles, hopefully I have better luck! 
What motor do you have?
What motor do you have?I have the 5.3L. I've owned a 2012 and 2014 Silverado with the 5.3L and never had an issue, ran them to 130k-150k miles. Sold the 2014 for this 2021 Trail Boss and now the dealer has had it longer than I have.I have never seen anything in writing regarding this, but it seems like the general rule-of-thumb is 5,000 miles. I hear that's how long you want to wait to change the oil too, for similar reasons. That's what I did. But dang, I have never heard of engine failures that early! I have the 6.2 and am at 42,500 miles, hopefully I have better luck!
clstark7
Active member
Maybe the previous owner wasn't very religious on their oil changes and was super hard on it. Along with probably sub-91 octane fuel regularly. Because I have heard of lifter issues but not complete engine failures on these 2019+ models. But at least you will have a brand new motor that you know will be treated correctly going forward. Hang in there, I am sure this new one will give you many miles.
Transient
Well-known member
Iirc, this was best to death on gm-trucks.com. I believe somebody found something in the owners manual about a 500 mile break in period of keeping the vehicle below 50 mph and staying off the highways.
This should help. If you go to the index you'll find a page listing for "Break in, New vehicle". In the 2019 manual is page 217. In the 2020 manual it's page 204. It's there, but you need to look in the index. There's also a separate section for towing. One of the first things it says is do not tow while breaking in the engine. There's other recommendations listed there, too.
https://www.chevrolet.com/support/vehicle/manuals-guides
This should help. If you go to the index you'll find a page listing for "Break in, New vehicle". In the 2019 manual is page 217. In the 2020 manual it's page 204. It's there, but you need to look in the index. There's also a separate section for towing. One of the first things it says is do not tow while breaking in the engine. There's other recommendations listed there, too.
https://www.chevrolet.com/support/vehicle/manuals-guides
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