Hi, new to the forum. I gotta 2012 gmc sierra 2500 LML diesel 250k. It’s been deleted (dpf). 3.5 inch lift, 20inch arkon lincolns, and 33inch ridge grapplers. I am not chasing big hp numbers but I want know what I can do to give me a some-what reliable truck that still has some extra get up and go. I understand the cp4 can be problem spot but I am meticulous about maintenance and I know a lot of people who have had good experiences with higher mileage trucks than mine. I know many will tell me to cp4 swap it but as of now I will not be doing so. I will likely do an excergy improved stock pump plus the other things like cat fuel filter and lift pump. I don’t mind putting some money into the trans either but I don't want to be running a built trans for now as i’m tight on funds. For around $4,500 (not including labor costs) what can I have done to this truck to make a quick-ish somewhat reliable rig? Any input is appreciated, thanks.
Reliable LML
- Thread starter Tin_man_LML
- Start date
I don't know the answer to your question, but my suggestion is that you driv your truck as is for a while, at least a year, to make sure it is rock solid reliable. Nothing worse and more costly than trying to improve a non-reliable truck. While you are checking this out, you can find out more about what you would like to do and also save up some money to pay for it.
Here's the c3 and c4 clutch pack from a 2015 LML that had a 50hp tune on it, trans had a pressure fooler. Sorry if you don't want to build the trans, but it's going to need it sooner rather than later if you want a "quick truck"
I would put a lift pump for sure and save up for a trans build. If you get a lift pump with filtration there really isn't a need to do a cat filter swap in the front.
Messing with a transmission with 250k on the clock is like a ticking time bomb...
Dumping $4500 into mods would be useless if you limp the trans and have to park it. Even if you try to sell the mod's, you will loose money on those items and still not have enough to fix the trans.
You also can't sell a broken truck for near what you paid for it either....
Messing with a transmission with 250k on the clock is like a ticking time bomb...
Dumping $4500 into mods would be useless if you limp the trans and have to park it. Even if you try to sell the mod's, you will loose money on those items and still not have enough to fix the trans.
You also can't sell a broken truck for near what you paid for it either....
Put the 4500 towards a built trans. Then moon tune and lift pump.
There's not many tuned LMLs that haven't had to have head gaskets replaced. Then you yank the heads off to find the pistons have hairline cracks in them..... Doing one up right now. Should have been a quick head gasket job and 2 pistons are starting to crack.
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HD Dave just cracked a piston a month or so,ago. He took the motor out and you can see cracks in 2 others as well. His spray pattern was outside of the bowl, I’ve looked and this is common on tuned lml’s. I believe this is the cause of the failures. The lml has large injectors for stock compared to other Duramax models and the piston is chased down from TDC just like every other Duramax but, it has a lot more fuel that is landing outside the bowl putting heat into the lip area. I told Dave to go ahead and get 100% overs to try and pull timing out to get the spray pattern back where it belongs. Hopefully it will help the new engine live longer.
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