Chevy and GMC Duramax Diesel Forum banner
  • Hey Everyone! Enter your ride HERE to be a part of this months Ride of the Month Challenge!

1 - 11 of 11 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
Hello all! I finally got the truck of my dreams having custom ordered, from the factory a 2021 2500 HD, CrewCab, 4x4, Z71. As of today it has 1227 miles on it and from day one there has been issues.

1st issue was pulling to the left which has now been back to the dealer twice and is still having same problem. I have noticed a knock coming from the engine compartment that doesn’t seem normal to me and have actually found on gm-tech link that this is a known issue with what seems to be a repair given by the company. Duramax Diesel Warm Engine Idle Knock Sound – TechLink

During the First day or two of driving, the Trip 1, Trip 2, and digital speedometer, mpg screens were present. Now they are nowhere to be found. I have the work truck trim, so base model odometer stem (no buttons on steering wheel other than cruise control). I scroll through all the available screens; air filter life, fuel filter life, brake pad life, tranny temp, etc. No trip or digital speedometer screens anywhere and I can't figure out how to get them back. Have tried everything and have also now found that is also another known issue. One guy took it to the dealership and they couldn’t figure it out and then a different mechanic decided to remove a fuse (wasn’t sure which one) and that got the first few screens back.

Last problem (at least it doesn’t seem right to me and I’ve read through the entire Owners Manual and Duramax supplement) is Exhaust Cleaning. Regen doesn’t seem to working while driving. At 1200 miles driving about 50% in town and 50% highway for 75 miles up the mountain to central Arizona and back again, usually in the same 24 hour period, there seems to be no self cleaning happening. Which means I sit in this things for 35-45 minutes in my yard while the neighbors think my truck I’m gonna blow up.

HELP!!

I’m taking it back to the dealer for the 3rd time (1st two for it pulling to the left...again still doing it) with the rest of these other issues.

P.S. I ordered the truck in August 2020 and took delivery Dec 12, 2020.
It will become my new company work truck and I only use it once or twice a week while I’m waiting waiting for a work shell, Decked slide out drawer system and other things.

I wrote this while waiting for the exhaust cleaning to complete and from beginning to end took 40 min on the nose. Just like the previous 3 cleanings.

Is this thing a lemon?
Thankyou in advance for any and all thoughts and advice.
 

·
Premium Member
Joined
·
691 Posts
How do you know regen isn't happening while you are driving?
 

·
Registered
Joined
·
5 Posts
Discussion Starter #3
How do you know regen isn't happening while you are driving?
I’m not sure but from what I’m reading, if the regen is working then why am I also having to clean the exhaust for 40 minutes when prompted...which has been once a tankful for for the first four tanks so far.
 

·
Registered
Joined
·
697 Posts
I’m not sure but from what I’m reading, if the regen is working then why am I also having to clean the exhaust for 40 minutes when prompted...
Prompted by what?
 

·
Super Moderator
Joined
·
791 Posts
@384xray , hello and welcome to the forums. Sorry to hear about your issues. Yes, the knock is a "normal" issue with the '20-'21 trucks. There is already a huge thread on here.

The regeneration cycle will not complete with the truck sitting still. After some time idling, the regen cycle will turn OFF, but I guarantee you that it did not complete. This goes for while driving (sitting in gear at a red light), or just in park. Assuming your truck is functioning normally (no check engine or other codes), if you see the "continue driving" message. You must drive the truck. Without some kind of OBD data viewer (iDash, Edge, etc.) the only way to tell if you're in regen is to watch your instant fuel mileage. It will be very poor.

Something I'm confused about, you're sitting in your truck for 35-45 minutes thinking your truck will blow up. Please forgive the question, but, what are you doing, and what is the truck doing? Do you already have an iDash or something, and you activated the stationary regen (not recommended)? Please tell me you're not sitting there revving the thing up...

BTW, excellent articles you should read to help you understand the process:
 
  • Like
Reactions: BoiseRob and sambor

·
Premium Member
Joined
·
10,296 Posts
Welcome to the DF!
 

·
Registered
Joined
·
5 Posts
Discussion Starter #7
@384xray , hello and welcome to the forums. Sorry to hear about your issues. Yes, the knock is a "normal" issue with the '20-'21 trucks. There is already a huge thread on here.

The regeneration cycle will not complete with the truck sitting still. After some time idling, the regen cycle will turn OFF, but I guarantee you that it did not complete. This goes for while driving (sitting in gear at a red light), or just in park. Assuming your truck is functioning normally (no check engine or other codes), if you see the "continue driving" message. You must drive the truck. Without some kind of OBD data viewer (iDash, Edge, etc.) the only way to tell if you're in regen is to watch your instant fuel mileage. It will be very poor.

Something I'm confused about, you're sitting in your truck for 35-45 minutes thinking your truck will blow up. Please forgive the question, but, what are you doing, and what is the truck doing? Do you already have an iDash or something, and you activated the stationary regen (not recommended)? Please tell me you're not sitting there revving the thing up...

BTW, excellent articles you should read to help you understand the process:
 

·
Registered
Joined
·
5 Posts
Discussion Starter #8
Thank you for all that information. I’m getting the prompt that says exhaust cleaning needed (not sure of exact wording) and to put in park and follow instructions. Right as that popped up last night I had a 75 mile drive up the interstate to do so after reading through the manual, I thought it might get cleaned with the drive. When I got home and put in park, I still got the prompt it needed cleaning so I proceeded to initiate the process. As I’m sure you’re aware, it basically revs up and the whole process...each time and so far has taken about 40 minutes. It’s pretty much every tank full that this has been needed.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #9
Thank you for all that information. I’m getting the prompt that says exhaust cleaning needed (not sure of exact wording) and to put in park and follow instructions. Right as that popped up last night I had a 75 mile drive up the interstate to do so after reading through the manual, I thought it might get cleaned with the drive. When I got home and put in park, I still got the prompt it needed cleaning so I proceeded to initiate the process. As I’m sure you’re aware, it basically revs up and the whole process...each time and so far has taken about 40 minutes. It’s pretty much every tank full that this has been needed.
I’ve also never gotten a continue driving message. It’s always exhaust cleaning and put in park and follow instructions. Hold exhaust brake for 3 seconds and then it initiates.
 

·
Super Moderator
Joined
·
791 Posts
Whoa weird. Dude, that is completely news to me. I thought only the chassis cab models had that, not the pickups. I dunno man, something definitely doesn't sound correct about what you're describing. Sounds like it's stuck in some sort of programming loop.
 

·
Registered
2019 GMC 2500 Denali
Joined
·
97 Posts
Just sounds like a run of bad luck few have sometimes. Dont give up on the GM trucks. I have had a 2019 for 2 years, only issue was DEF showing low when full. Just air in the system and a known issue during assembly. They say never buy the 1st or 2nd year on any brands new model ... broke that rule and have a 2021 on order. Hopefully they get all your issues worked out.
 
  • Like
Reactions: 384xray
1 - 11 of 11 Posts
Top