2025 Gmc At4 2025 Diesel Problems. I found a diesel denali ultimate on a lot and it’s fantastic. The big news is the duramax diesel engine, with is surprisingly smooth and quiet.

View all 26 consumer vehicle reviews for the 2025 gmc sierra 2500hd on edmunds, or submit your own review of the 2025 sierra 2500hd. Hi,i’m currently considering purchasing a gmc at4x with the 6.2 engine, and i’ve heard about potential issues with dfm (dynamic fuel management) lifter failure.