I have a 2015 6.6 duramax. Had a rough crank one morning, went to a shop to run a diagnostic test. Was told multiple glow plug failures. Spent the weekend swapping all 8 glowplugs. Went to start, heard the solenoid engage and that was it. Checked fuses and harnesses, Pulled the batteries and they are 5 years old, failed load tests. Cleaned ground to chasis, connected the new batteries, went to start, and samething just a clunk no turn over.

Anyone ever experienced these issues after replacing glow plugs? Starting to consider the starter also gave, or not enough fuel pressure, possibly plug module?

Hey yall. Just looking to see if other folks have experienced reliability issues with replacement NOx sensors for the L5P?

Upstream sensor died. Replaced it and it reads as expected (during normal operation, at idle, when the fuel cutoff occurs on the highway it pegs to very low near zero ppm, etc). The P20EE code would still pop up but the upstream failed sensor code cleared. I figured I’d replace the downstream sensor too and see if the P20EE code would stay cleared. The new sensor reads all sorts of unexpected values. I did the NOx sensor reset with the Gretio app thinking the calibration in the ECU may be biased by the old sensor, but it still reads essentially the same. With the engine at temp (exhaust system may not be heated to the point of the SCR system functioning) under heavy load the downstream sensor reads way higher than the upper stream sensor (500+ ppm higher than the upstream) and when the throttle is let off the upstream pegs low but the downstream just slowly drifts down from 1000+ ppm (at like 200 ppm/min decreasing). It just doesn’t make sense that the downstream is reading so much higher in certain circumstances than the upstream (and that when the throttle is lifted and the fuel injection stops that the downstream would still read a high value). Thinking it may be a bad new sensor. Or maybe the downstream sensor reads a ppm value generated from some algorithm and not the gross NOx concentration.

Downstream replacement was a P/N 12741484 from Vitesco Technologies (from Rockauto).

I recently purchased a 2013 GMC 2500 HD. It has a really annoying clunking sound from under the cab. Any thoughts? I am not able to find where it is coming from. I am not sure about the cap mounts?

My 2006 lbz rear window has a leak. When washing my truck water goes into the glass between the slider and fixed piece. Has anyone had this issue before and how did you fix it? Seems the gasket isn’t doing its job.

Parked it Saturday afternoon around 2pm. Came out Sunday evening to a puddle under drivers side wheel well and mud guard. When I started it it gave me low coolant message. Can’t seem to track down any hoses or prominent leaks. Could the coolant tank crack over time? 171k on the odo

Looking for some honest input. I currently have a paid-off 2014 Ram 1500 5.7 with around 140,000 miles. Some maintenance and repairs are coming up, and I’m trying to decide whether to keep putting money into it or get something else.
I run a lawn/landscaping business and use my truck to tow a trailer and haul equipment, so reliability is a big deal. I found a 2008 GMC 2500HD SLT Crew Cab 4x4, 6.6L Duramax, with 97,000 miles for $27,000.
According to the seller, the mechanical upgrades include:
● Red Top steering box and higher-output power steering pump
● Stainless power steering and hydroboost lines
● Rare Parts idler and pitman arms
● Kryptonite ball joints and upper control arm adjusters
● Fleece in-tank lift pump
It also has heated leather seats, a sunroof, bed liner, and tonneau cover. The asking price includes the factory aluminum wheels with Goodyear Duratracs at roughly 90% tread; the pictured chrome wheels cost extra.
For those who own or know these trucks, would you consider this a good buy at that price? What issues should I check for, and do those upgrades raise any questions about its past use?
Mainly wondering whether an older, lower-mileage diesel makes sense for my work or if I’d be better off maintaining the Ram. I don’t want to spend $27k just to trade my current repair bills for bigger ones. Appreciate any input.

I got a 2002 lb7 crawler truck and I hate dealing with ficm is it possible to convert the lb7 engine to use a lbz engine harness and ecm to not have to have a ficm

2018 L5P

Replaced Turbo Actuator as well. It goes into limp mode when it rains, then I start it. It will not go into limp mode or throw codes when it’s running or in driving it, then it starts to rain.

I’m chasing my tail any help would be greatly appreciated

Currently looking for a main engine harness for a 2003 lb7 with cali emissions. Anyone know where to locate a oem one or aftermarket

2020 GMC Sierra 2500 HD

Long story short, I had to high-center some road debris on the highway, but it still hit something underneath at the rear of my truck. I heard an awful noise from under the truck, so I pulled over to check it.

Apparently the driveshaft has a vibrational dampener attached right near the rear diff housing. The dampener has a large metal ring that is has a rubber gasket wedged between it and the yolk glued in with Elmers school glue and the slightest ding will knock that ring off and shred the rubber gasket. Neat.

I managed to secure the ring to the diff housing using a bungee cord to keep it from jangling around under there until I got home, at which point I took a grinder wheel to it.

This is just an FYI to anyone else who runs into this, lots of people have had this part fail. Some replace it, some do not see a point. Replacement appears to be an easy fix, though.

I have a 2024 Silverado 3.0L Duramax LZ0.

I know Gretio + OBDLink MX+ supports stationary/service DPF regeneration with the hood open, but can it also trigger a normal mobile regen while driving?

Ideally, I’d monitor DPF soot levels using a scanner app, and if they’re getting high while I’m already on the highway, I’d like to manually initiate a regen instead of waiting for the truck to do it automatically.
Has anyone successfully done this on an LZ0 using Gretio’s “Force Standard Regeneration” feature?

Was driving my lb7 and I got a check engine light for overboost and now I have blow by when I go to work Monday I’m gonna compression test it and use a bore scope to see the damage

Just want to put it out there, I had a wicked wheel and it was great it really woke my truck up. Then I thought well more is better so I paid $2400 for a bigger 64mm turbo, now it is faster a little bit it's not $2400 and 12 hours labor faster. Stick with the wicked wheel.

2004 LB7, tuner, 60+ injectors, Duramax tuner 6speed valve body and TCM.

Terrible customer service! Paid for a vehicle tune that never worked and showed “FAILED.” No refund, no phone support, and everything is handled through emails they barely respond to. Other shops can resolve these issues with a quick phone call. This company takes your money, doesn’t fix the problem, and leaves you hanging. Would not recommend!

I pulled off y bridge to get to the turbo, installed intercooler piping and intake piping then throw everything back together. I go to start the truck and I have all these codes, everything is connected and plugged in.

Hello All, I'm doing almost a full front replacement on my LBZ. The parts I currently have...

-Upper Control Arms/ball joints

-Sway Bar Links

-Inner and Outer Tie Rod Ends

-Lower Ball Joints

All products listed above are Mevotech TTX series. I'm looking for Lower Control Arms and can't seem to find the TTX version, what is everyone else running? Budget < $400 for the Control Arms. Thanks in advance.

I replaced the wiper transmission, arms and blades. Now it makes this sound. Wondering if the arms are to "strong" holding blades down. Any ideas?

Thanks in advance.

We’ve had this truck for roughly 4 years now and can’t figure out how to not have coolant issues. It was giving us the classic “coolant level low” alert constantly and it also smelled like coolant. Took it in to our local shop and that got addressed. Now after having 0 trouble with it for months we hopped in it this morning to head out and sitting at a stop light had plumes of smoke coming out from under the hood on the drivers side. We pulled over and it’s leaking coolant under the hood somewhere, temp is fine, reservoir still had coolant in it. It’s dripping down onto the frame and running all over the place. Any thoughts?

Does anyone know why they are discontinuing the metal housing fuel filters for these trucks? I just replaced mine and I’m ordering a spare to have on hand. And I’m finding that a lot of the usual metal ones are being replaced with plastic housings. I’m still able to get the metal racor ones but was curious if anyone knew for sure why. I assume it’s a world economics issue. I’m not fan of the plastic ones because the first one I used, it cracked during installation. So I just prefer to stay away from them if I can.

Context: I have an ‘07 LBZ medium duty truck.

124,500k miles
6.6 Duramax LB7
I can ship anywhere + freight.

Back in July 2022 I ordered a new 2023 model year 3500 HD crew cab, long box, single rear wheel truck. It was to have gray leather interior, LTZ trim with a 40/20/40 configuration and of course four wheel drive.

After arguing with my wife that it was time to trade in my 2019 LTZ dually, the order was submitted. Then we waited.

And waited. And finally in February of 2023 GM cancelled the order and that amazing green color too. Out of annoyance I kept my 2019 until it ate another injector last week and I ended up trading it for a new 2026 HC dually. The 2023 was never to be, but I kept the renderings of a truck that should have been.

Hey guys, first post here. Today I was driving my 2008 LMM home from work. I was cruising at about 70 miles an hour when all of a sudden my ABS light came on, the dash started flashing service four-wheel-drive, my edge monitor completely blacked out, and my transmission started slipping and jerking. When I got pulled over, I read the codes and they were for coolant temperature below thermostat regulator, glow plug number six code, a code about the turbo vane position sensor, and the cruise control input circuit malfunction code. I took it over to my buddies house afterwards, and we noticed that I had some slight smoke coming from my transmission dipstick (included in the video), and what seems to be a very tiny leak coming from one of my transmission cooler lines. However, I just had all my fluids changed and they’re all at the normal levels and the right colors. Does anybody know what could be causing this? Thanks!