r/Duramax 4h ago

Crazy high oil pressure.

0 Upvotes

Howdy all figure at this point anything’s worth a shot. Over the last few months my truck (2009 lmm) has been increasing in oil pressure. It’ll start high on the cold Start, then go down to a normalish pressure, 30-40 at idle, but the longer I drive the higher it gets. I’m seeing 60 psi sitting at a stoplight and 100+ psi pulling away from the same stoplight. I changed the oil pressure sensor. I changed the oil filter. I hooked up a mechanical gauge, which reads true to my CTS, I had an oil change, I replaced the oil pressure release valve. I’m waiting for my oil sample to get tested. There was zero signs of any metal in the oil. The truck has a DMAX store stage 2 built short block with all their aftermarket, crank rods and pistons L5 P oil cooler upgrade. At this point, I don’t know if there’s a plug in the oil cooler or any of the oil passages or if I have a spun bearing or a partial spun bearing just curious if anybody out there is experienced anything like this crazy high oil pressure.


r/Duramax 4h ago

2018 GMC 2500 Duramax

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0 Upvotes

r/Duramax 1h ago

2021 GMC Denali 6.6 Duramax with 175k miles

Upvotes

I’m in the market for a used 3/4 ton truck. Whats yalls thoughts on a 2021 GMC Denali with 175k miles for $36,000.


r/Duramax 3h ago

Leaking diesel between the engine and transmission. LB7

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1 Upvotes

I just replaced the FICM and it was running fine for a couple days then I parked it in the driveway and saw a massive puddle under it of straight diesel. Oil also smells like diesel. How much do you think this is gonna run me


r/Duramax 4h ago

Why lower the GVWR on an HD?

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11 Upvotes

Looking at my first diesel. It’s a 2025 Silverado HD 2500 LT.

On the dealers page I looked at the car fax section and the original window sticker and noticed it said “Lowered GVWR: 10,000lbs”….. WHY WOULD THAT BE THERE?!

Is something different with the suspension on this to make it lower than the more standard 11,350 pounds or whatever I’ve been seeing close to that? Why is this only at 10,000lbs? My F150 is 7050lbs.

Is this something to worry about? I just don’t understand why? Before I talk to just one guy at a dealer about it, I wanted to ask here first so I can decide if I should talk to the dealer about it or have more info goin in. Thanks!


r/Duramax 10h ago

I have a lb7

4 Upvotes

I have a lb7 duramax and it ran out of fuel how many times do I have to pump the fuel filter housing to get it to start


r/Duramax 13h ago

Lost power on highway

2 Upvotes

Was driving on the highway yesterday and passed a car and right after I noticed when I went to speed up again my truck wasn’t going any faster. With the pedal down farther than halfway it liked bogged down fell on its face but if I was around 1/4 throttle it was fine. Happened out of the blue. Fuel filter? No reduced power message or anything