Originally Posted by PRKev
What year Duramax and mileage on the fuel injector replacement? Got what I thought was a good deal on a 2012 Chevy 2500HD, only 25,000 miles. The transmission control went out after about 3,000 miles, was stranded in key west so had to pay the dealership $1100 to fix it. Got an extended warranty until 75,000 miles that will cover the fuel injectors
I had about 150k on mine used at it was an 06. Long story, short but buying from a guy that never towed anything worked against me because as the injectors start to fail the guy that never tows will not notice. Honest guy that had no idea. I got a check engine light and limp mode the first time up the CA grapevine. I found a good independent diesel mechanic and he said 150k or so and this starts to happen on the Duramax and the guy that never tows would never notice and not care. Sounds like you should have a long way to go at about half that mileage. There are a few workarounds to help such as installing a lift pump as the Duramax doesn’t come with one but I was told that just delays the problem and you risk grenading the injection pump which blows metal particles through everything and then it is a cab off major job to repair.
I would suggest loading your trailer as heavy as possible and take a highway run up a steep grade in the heat at about 70k. That will require max pressure on the injectors and if they are clogging or hanging open you will get a check engine light and limp mode. Your engine temps will likely get real hot too. If no issues then you are probably fine.
Also, the Allison tranny is generally considered great (not sure about your controller) but not serviceable so when that goes you have to replace. My mechanic told me that if shifts into reverse start taking longer and getting jerky then you are on the way. I never had any issues with mine though.
OP—sorry for the thread hijack. But all with the intention of sharing and helping forum members.