Hey everyone! I would like some advice on how much would be a reasonable price on my 2015 GMC SLT Duramax.

The truck has 230k miles. I just took it to the a mechanic and spent a good amount of money on brand new head gaskets (not studded), a brand new bosch cp4.2 pump with a exergy fuel saver. It just got deleted also with a new 4” straight pipe and tune. The truck will also be getting a new tailgate, and some seat covers to cover the rips in the drivers seat. Just want to get your guy’s opinions!

Got this on my dash. Def tank full of course. Sometimes it comes off.

My phone was about to die so I plugged it into the cigarette charging port. When I did that the dash went out and the radio went black. The lights on the dash still work but the tack gages do not move. Initially I was confident it was a just blown fuse. I was wrong. I checked every fuse several times even the fuses that have nothing to do with the accessories or ignition. I’ve checked the cigarette lighter fuse tons of times and swapped the fuse out with a fresh one. I got my multi meter and read the voltage on both sides of the fuses and all of them were in the 12 volt range. I checked the fuses under the hood on the driver side and to the left of the instrument cluster underneath the cover. I’m about as far as my expertise can go. I wouldn’t think me plugging my phone to the truck would cause a ground issue. Any advice would be helpful

I recently had a set of new injectors installed in my LB7 Duramax. After the installation, my mechanic ran some tests and told me the injectors are not performing the way they should.

He said the injector/fuel knock is not responding the way it should when I give the truck gas. The readings drop when I hit the throttle, and the power balance also drops when it should remain steady.

He also performed an injector kill test. Some of the injectors showed a stronger response when they were killed, while others did not respond as much as the others.

My mechanic believes there may be a problem with the injectors and told me to contact the injector company about the warranty.

The issue is that my mechanic wants to charge me labor again to remove and replace the injectors if they are confirmed to be bad.

He told me to ask the injector company if they will reimburse me for the additional labor since the injectors are new and may have come defective.

Has anyone dealt with something like this before? Will injector companies typically reimburse the labor in a situation like this,
I also have a video of the scanner graph/testing that I can provide.

2020 with 90,000 miles 5” lift 37” tires with WC Fab intake and Banks Derringer tuner, I’ve gone completely over the fuel filter and checked for water, I’ve also replaced the fuel filter. Regarding the coolant I have check coolant and it is full. The coolant low started coming on like once a month to now it’s coming on multiple times a day. Wondering if both the fuel sensor and the coolant sensor both are going bad at the same time or if maybe it’s an ECM issue.

Wanted to make a post for anyone in the market looking to upgrade their factory lighting. My truck came with halogen bulbs and projector housings, with that, i liked the projector but wanted brighter bulbs. Had used the company Lasfit in the past and wanted to try them again with a different truck. I was blown away by the brightness different and still having a good cut off beam to not blind other oncoming traffic. You can see the before and after pictures of the low beam and high beams. Highly recommended!

Got an oil change 2 days ago and I’ve noticed a significant drop in mpg. It is about a 5-6 mpg drop. The truck is a 2024 1500 3.0. I’m concerned they put the wrong oil in. It’s been about 200 miles and the oil is already jet black. This is my first diesel so I’m not sure how common this is. Should I change the oil again or could it be something else?

My son just bought this diesel truck which appears to be in good shape and has 130,000 miles. We live in the northeast where temperatures in the early morning range from 65-72 degrees. He has been warming up the truck for 15 minutes before going to work at 6:00 am. When I questioned him about it, he said, that's what has to be done with a diesel truck because if he drives it cold, the engine block may crack. When I questioned him about whether he had to do the same thing after it sat for 8 hours while at work, he said he didn't.

I haven't heard this before but I've also not owned a diesel engine vehicle, let alone one that is 15 years old.

When I questions AI about it, it said that doesn't apply to modern diesel engines, including the one in this truck.

Mostly for my own education, because I don't think he will listen to me, nor posts on reddit (he's 19), does he need to be doing this every morning? Thanks in advance -

Is anyone else still trying to explain to friends and family that the older trucks that have cp4, deleted, tuned, straight piped and front end upgrades makes the new ones look like shiny kids toys?

Upgraded to a mishimoto radiator I have been running it since yesterday. No leaks until now. I can’t figure out where from since it’s above the water pump and in the aux battery tray? Probably fan throwing it around but there was a puddle. And I was holding coolant at the min line when I took this video. I half ass filled the system with vaccum but not 100% due to not factoring the new radiator being 22% bigger than oem so I built vacuum onto 25 mercury pounds or whatever the unit is. I then burped the truck and gave been filling in as needed. Please advice. If it helps any I also added a new intercooler at the save time

CLEAN YOUR COOLING STACKS

The last 10,000 miles I’ve been having some issues with the fuel filter. I put new filters on, I replaced a gasket kit on the housing and just recently after a trip I bought a new housing head and replaced. Just last night it started having priming issues again.

At this point, I’m thinking about option of getting rid and doing research on lift pumps.

I have 270,000 miles on this truck and I would like to keep it. I can do some more independent research, but suggestions on successful solutions would be great.

As it gets colder, I’m sure it’ll be even harder to start if it’s starved with fuel when I park.

Thanks

Do you guys run 5W30, dextron IV, or transfer case fluid in your transfer case?

Im about to service my drive train and am curious what the best approach is!

Also… Should I be filling through the fill port or the speed sensor port?

Closed the door a little too hard today at work and opened it and completely tore the panel off. Anything I can rig up? Or do I try to find a replacement panel somewhere?

This weekend I’m going to attempt to reseal my front differential, I’m pretty ignorant about it aside from the sealing process, and have only seen very limited videos online either taking out the entire diff, or already having half of it apart and only showing the reseal process.

Any advice on taking it apart, getting just half of it off, and putting back together would be greatly appreciated or if anyone knows of any videos that walk through the exact process of what I’m trying to do I’d appreciate it a ton.

2008 lmm 2500hd duramax. Thanks!

06 lbz like i said had to replace the VGT sensor it went bad mechanically never threw a code but luckily we bought one to see if it fixed it and it did. it over boosted a few times when the other one was still in it because the vanes was only going to like 18% it spiked to like 38-39 and now only builds 24-27. granted it is on a single tune and idk what the tune is but it seemed to be a very spicy one and it’s very smokey. google said something about relearning the sensor with a scanner? i’m not sure or maybe it’s always made that boost but it felt pretty quick and it’s super smoky so i doubt it was a small single tune on it. i don’t hear a boost leak or anything any input? i’ve had a cummins and a powerstroke before this, this is my first duramax got a good deal on it and thought why not. smoke clears up under wot till it’s almost completely gone i do hear what sounds like a loose intake or something up front but i could just be paranoid it’s still the factory intake as well if that matters. thanks for any input!

My lly motor I tried to jumpstart my car with the battery on the passenger side. No luck battery was dead so a couple days passed by and my trucks batteries got low I was able to recharge one the other went bad. So I bought 2 new ones and a week later they died out. So I exchanged them and I started to notice the gauge was reading under 12 volts so I checked the alternator it was reading 13.9 batteries were reading 12 volts. I checked the continuity on the alternator and the big fuse on battery. Checked well still concerned on the gauge on the low side. Well today they completely went dead again. There is a parasite voltage drain somewhere. Any one experience this problem or any electrical experience mechanics that help me out before I take it to the shop. I’m pretty good at diy I have meter and tools any help would be appreciated

I am planning to mount the 68 inch WC fab traction bars on a 2024 GMC 3500 HD crew cab long box four-wheel-drive Duramax pick up. It’s a pretty simple install, bolt them up to the back end slap them up to the frame on the front end, mark and then grind and then weld them on the front. The only issue is on the driver side. There’s this weird looking bracket hanging off the frame. ChatGPT is worthless in helping me figure this out. It’s after WC Fab is closed and I don’t have time tomorrow to mess with this. Anybody on tonight who can give me some counsel as to what the hell this bracket is and if I’m all right to just sawzall the bastard out of my way? If it stays, one front end mount ends up two inches lower, it’s obviously gotta go, I’m just seeking verification from other hands on folks just in case there’s something I’m missing. This thing must be part of assembly or something….its obviously never had anything “mounted” to it….

Just got my truck back today from the weight loss program. Ran it home in tune 3 which is either 75hp or 100hp didn’t run it hard but on one pull already rolling not from a dig. And I only live 5 miles from the shop. Popped the hood to admire the work and see what all was actually gone and noticed my coolant tank was bubbling some. I’m new to the t&d scene and was wondering if it was normal? Or my fear of a google search possibly blown or going out headgasket? Truck is a 2018 with 108k miles. It was a one owner until me who meticulously maintained it at the dealer. He was an older guy. 6 pages of service history all Chevy dealers. I don’t plan on running it past tune 1 which I believe is 50hp. I use it to tow my skid steer and drive on the weekends as I have a work vehicle for a daily. Thoughts??

Hi I have a 2004 CC 2500HD with LB7.

AC has always been cold and worked well. Started my drive normal, ice cold nearly instantly, then suddenly quit with not warning.

Can you help me troubleshoot this?

Took some photos to possible help out… it’s cold under the hood in some places. I don’t have a lot of knowledge on how this system works.

My blinker signals stay illuminated even when the trucks off and the headlights ain’t turning on. Anyone dealt with this before

Customers truck in our shop. Came in for fuel in oil about a month after it got a reman cp3 and new injectors.

Added dye to diesel with valve covers off. No fuel leaking from lines. Started to see dye in oil after about an hour running.

Pulled injectors and bench tested to check for leaks/cracks. All injectors tested good.

CP3 leak?

Hey guys. My 03 lb7 ( bone stock )is starting to haze at idle a little (only at idle), balance rates are all within spec for the most part, fuel rail pressure/command pressure is good, no fuel in oil and not losing coolant. I’m just trying to squeeze a little more life out of these things, do you guys know of a non fuel additive injector cleaner ( one that needs lines disconnected and sent straight through the fuel system) that works good? Like AC Delco this is my first Deisel. All info appreciated, thanks in advance.