r/Duramax

Buddy offered to sell me his 2015 GMC 2500 but head gasket is blown... What would I be looking at to repair it?

Idk the first thing about diesels but I know lefty loosey righty tighty. I can turn wrenches and I'm not afraid of the job itself. He's asking 8k for it. I might scoop it unless y'all tell me it's a bad idea.

What do? Is it a cab off job? 150k miles. 4x4. Pretty nice. Interior is kinda trashed but the exterior is clean. Idk. Debating.

reddit.com
u/some_kind_of_friend — 3 days ago

2026 L5P Fuel Mileage

My first long run towing 8k lbs, round trip of about 3500 miles.

Really surprised, compared to my 04 LLY where I got 18-20 might.

On my 2026 I got 10-11 mpg.

Is this normal?

Besides that no issues, was a great truck, 8k was too easy lol

reddit.com
u/TG_2023 — 10 days ago

06 Silverado duramax 2500 lbz

Help me out community, for you people that actually know what youre looking at here. Help me to better understand balance rates and what not

u/WPenwright_3 — 11 days ago

New Sound Unlocked

Okay, so I shut my truck off yesterday and realized that we unlocked a new noise!

2013 GMC Sierra 3500HD (LML)

Yesterday I also realized that I have a small diesel leak if I leave the key on RUN for an extended period of time. If the truck is running, there is no leak. No big deal. However, this noise is stressing me out. It sounds like someone is in there with a little impact gun! Nobody can seem to shoot me a straight answer on this one. Hopefully one of you can help me.

Note: If I were to go to the truck right now, turn the key to RUN and then turn it back off, it'll make the noise again. I can also just barely hear it steadily while the engine is running.

u/420steamfitter — 11 days ago

Looking for advice on exhaust butterfly valve bypass

2023 T&D

Initially did a 5” straight pipe but my family hated the drone and I wasn’t a big fan on highway trips.
Got a muffler installed, all is well.

Now admittedly I miss the straight pipe sound and would love a muffler bypass line welded in, with a bypass butterfly valve.

Is this easily accomplished? Should I just use a mechanical valve instead? Or would the exhaust shop look at me like I’m an idiot?

Thank you!

reddit.com
u/Mcfragger — 11 days ago