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New Duramax issues?

Baconator

Well-known member
Joined
Jun 1, 2020
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Its time to replace my 02 LB7 Dmax, it has served me extremely well and I really cant complain about it at all.
Looking at 2020/2021 GMC 3500's to replace it.
Wondering if there are any known issues with the L5P Dmax that I should be aware of. The truck will NOT be deleted, as I am now considered commercial and needs to be able to roll through a weigh station or pass inspection without issue.

I considered Ford, however they still seem to have issues with their fuel system and wont warranty them. So I am sticking with GM. Hell no to Dodge, wont ever make that mistake again.

Hold your comments about buying a new truck, my business is buying it and it makes sense for it to do so.
 
Dodge/ford still run a problematic CP4.

GM learned from their mistakes and currently run a delphi pump with so far, so good, results. It's just the ugliest fucking truck ever made. The 10spd is also a joint venture with ford and has fuck all to do with allison.
 
TRINDU said:
Dodge/ford still run a problematic CP4.

GM learned from their mistakes and currently run a delphi pump with so far, so good, results. It's just the ugliest fucking truck ever made. The 10spd is also a joint venture with ford and has fuck all to do with allison.
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Thats why I wont consider a Chevy, the GMC isnt nearly as ugly.
Ive never thought the allison was that great anyway, its never given me issue but the gear splits are garbage. I was considering a 2017-2021 until I found that they went 10spd in 2020.
 
No major issues on the L5P so far that I've seen. I replaced a handful of glow plugs, injectors, and particulate sensors. The 10 speed seems to be trouble free so far.
 
bradp674 said:
Not that answers anything for you, but it looks like Ram is going back to a cp3 style pump for the new 2021 rams with 1075 lb ft of torque.

https://moparinsiders.com/ram-moves-away-from-the-cp4-2-injection-pump-for-2021/
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Does Dodge still derate their Cab and Chassis trucks? I cant seem to find an answer to that other than hearsay. A good friend that I contract with has a 4500 that is gutless because its derated compared to a regular 3500.
My dad also had a 2019 1500 that was a giant POS from the day it rolled off the dealer lot, I am soured on Dodge now due to his experience with it and how Dodge corporate fought everything until he finally got a lawyer and forced them to buy it back. I think its the best looking truck out there, but not sure if I can stomach one.
 
It looks like they still do with max torque at 800.

I'm like you, the Ram is the best looking, but I think it would be hard to buy any of the top three with the prices and reliability issues, and then count on them for a business.


6.7L CUMMINS[SUP]®[/SUP] TURBO DIESEL I6 ENGINE


The Class-Exclusive available 6.7L Cummins[SUP]®[/SUP] Turbo Diesel I6 engine( Disclosure2) is remarkably lightweight for impressive responsiveness and efficiency while offering exceptional torque on 4500 and 5500 models for outstanding towing and hauling capability. A fully electronically controlled transmission, the Aisin six-speed automatic transmission has been optimized for powerful towing capability on Ram 4500 and 5500 models and features software control for seamless shifting. It is available across the 2021 Ram Chassis Cab lineup (excludes Ram 3500 10K models) and offers Power Take Off capability.

MAX TORQUE (4500/5500 MODELS)
800 LB-FT




BEST-IN-CLASS MAX TRAILERING( Disclosure1) (5500 MODELS)
35,220 LB




BEST-IN-CLASS MAX HORSEPOWER( Disclosure3) (4500/5500 MODELS)
360




MAX GCWR( Disclosure1) (5500 MODELS)
43,000 LB
 
Neighbor was looking at new GM’s and claimed there are some complaints about knocking. No idea if it’s true. He’s now looking at Ram instead.

have a 21 Ford. It’s okay. The 10 speeds is somewhat confusing at times. Seats are a huge improvement, but hindsight being what it is, I should have kept the 16.
 
TRINDU said:
The 10spd is also a joint venture with ford and has fuck all to do with allison.
Click to expand...

I thought that was only the light duty 10spd used in the F150/Camaro that was a joint venture and the HD 10spd was all new Ford only or GM only for theirs?


Found this on the trans: The 10R140 is not to be confused with the 10R80 10 speed automatic transmission found in the Ford F-150 that was co-developed between General Motors and Ford Motor Company, nor is it an adaptation of the lighter duty transmission. Both the gear spread and physical design of the two 10 speed transmissions differs and there are minimal, if any shared components.
 
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Wheelerfreak said:
I thought that was only the light duty 10spd used in the F150/Camaro that was a joint venture and the HD 10spd was all new Ford only or GM only for theirs?


Found this on the trans: The 10R140 is not to be confused with the 10R80 10 speed automatic transmission found in the Ford F-150 that was co-developed between General Motors and Ford Motor Company, nor is it an adaptation of the lighter duty transmission. Both the gear spread and physical design of the two 10 speed transmissions differs and there are minimal, if any shared components.
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Right, the 10R80 and 10R140 arent related.

However, the 104R140 and GM 10L1000 are. They're not identical, but share a lot of the same architecture. Still, Allison was only retained for (stupid) branding reasons.

GM on left vs Ford on right.

10spd fuckery.jpg
 
How come 90% of the people shopping for $50-80k trucks only seem care about the engine?

Is the Ford fuel problem really a big thing? I know probably 2 dozen people with 6.7 ford's and none of them have had this "super common" issue. Also seems like 80% of work trucks are ford's and a fair margin of those are 6.7s. So any issues will seem more common when there is 10 power strokes to every 1 duramax or cummins.

I try to be unbiased, but I just have a hard time trusting any late model gm or fiat shit. If the duramaxs were as good as the owners say, why does nobody buy them?
 
Baconator said:
Does Dodge still derate their Cab and Chassis trucks? I cant seem to find an answer to that other than hearsay. A good friend that I contract with has a 4500 that is gutless because its derated compared to a regular 3500.
My dad also had a 2019 1500 that was a giant POS from the day it rolled off the dealer lot, I am soured on Dodge now due to his experience with it and how Dodge corporate fought everything until he finally got a lawyer and forced them to buy it back. I think its the best looking truck out there, but not sure if I can stomach one.
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I think they all do that. They are assuming that some idiot is going to be driving it that doesn't care about it, which is often true.

I wonder if the dealer could reflash it for you?

Thats gotta be so terrible only havimg 375 hp and 800 ft lbs, how can he even drive it? :flipoff2:
 
YotaAtieToo said:
How come 90% of the people shopping for $50-80k trucks only seem care about the engine?

Is the Ford fuel problem really a big thing? I know probably 2 dozen people with 6.7 ford's and none of them have had this "super common" issue.
Click to expand...

I've seen bills anywhere from $8,000 to $18,000 for a 6.7L fuel system depending if the dealer is trying to fuck the private owner or a major company.

dont you hate on the CR 5.9L?
 
TRINDU said:
I've seen bills anywhere from $8,000 to $18,000 for a 6.7L fuel system depending if the dealer is trying to fuck the private owner or a major company.

dont you hate on the CR 5.9L?
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I'm not doubting it, just curious how common it is. Also, what is the actual cause? How can it be prevented?

I don't hate on them, Its just hard to justify the insane cost of a decent used one with the unknown of their issues. Out of the few people who I know who had them, all had minor to catastrophic injector issues, not one still has their truck, might say something. On the other hand, if I were to own a dodge, it would probably be an 04-05 6 spd/5.9.

What does that have to do with this thread again?

All I'm getting at is that for whatever reason the internet, when it comes to diesels, seems to like to hate on ford's. When my personal experience doesn't always line up. I don't know if it's different by region but I literally see probably 20 Ford 6.7s to 1 ram 6.7 and 1 duramax. Most of which are work trucks getting treated poorly. If they are as bad as the internet says, they would be strewn about the shoulder everyday.

The complexity of the new trucks scares me no matter which brand. We have a 2015 1/2 ton, but it's still, I believe, under the extended warranty. I could have gotten a diesel with a little more miles and no warranty, but I think if I got an $18k bill from a dealer I'd end up in jail :laughing: that being said, I don't think it's exclusive to diesels. Any new vehicle is complex and expensive to repair.
 
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YotaAtieToo said:
I'm not doubting it, just curious how common it is. Also, what is the actual cause? How can it be prevented?
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CP4 failures aren't limited to just ford Ford. It's common in GM, Jeep/Ram, and VW TDI. There are multiple class action lawsuits. The piston/cam is said to have lubrication issues from ULSD and grinds itself up, sending shavings thus compromising the entire fuel system.

Its prevented by not owning one or swapping to a CP3. Ford just loves to say fuck you, you bought "bad fuel" or put def in the tank. They absolutely refuse to admit its an inherent design flaw. So fuck a 6.7L
 
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I dont have a new 20/21 with a ten speed but i have a '17 with the L5P, 65,000 miles and not a single issue. Towed all over the place from Colorado- CA, UT, SD, etc handles all the passes with ease.
 
I've had a 2015 (2500) and 2017 (3500) Duramax. I now have a 2020 (3500) Duramax. I've had no issues towing with any of them. I just put 4,000 miles towing from Michigan to Utah and back (through Colorado) pulling a 38 ft enclosed trailer @ 17,000 pounds. We pushed the speed up to 80 wherever possible. No issues. Averaged 8.4 mpg. The only think I dislike about my 2020 is the bluetooth sucks compared to the 2017 and the DEF tank is too small.
 
If it’s like the 2019+ 1500s, they possibly will have issues with the rear window leaking. Apparently, GM did a poor job sealing some from the factory. There are also some issues with the infotainment system on some trucks. Screen will black out from time to time.

The front end of the chevys is extra fugly on the WT trimmed trucks. They don’t look as bad on the higher optioned trucks. That is all relative to them being uglier than any other HD truck.
 
Shopping for a 3/4 ton truck, fully trimmed to replace the wife’s older Yukon, her commute is like 1/2 mile a day. Want something comfy for our family of 4 to tow a camper. My old 2nd gen dodge Cummins will tow most anything, but something newer is a must for her. My rig is a beater firewood and camping pig. I won’t order a diesel for her, it’s between the 6.6 gm, or 6.4 ram.
 
Mvanhelden said:
Shopping for a 3/4 ton truck, fully trimmed to replace the wife’s older Yukon, her commute is like 1/2 mile a day. Want something comfy for our family of 4 to tow a camper. My old 2nd gen dodge Cummins will tow most anything, but something newer is a must for her. My rig is a beater firewood and camping pig. I won’t order a diesel for her, it’s between the 6.6 gm, or 6.4 ram.
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You cannot beat the interior in the new ram.....

I Just came out of a 2020 f350 and owned a 19 ram rebel...the 19in screen and interior of the ram is :grinpimp:


I only had the ford 350 tremor for 10k miles ..but the new 10 speed was nice towing my toyhauler at max weight...I was impressed...


And I would not own any of the big 3 diesels out of warranty :laughing:
 
DT75FLH said:
You cannot beat the interior in the new ram.....

I Just came out of a 2020 f350 and owned a 19 ram rebel...the 19in screen and interior of the ram is :grinpimp:


I only had the ford 350 tremor for 10k miles ..but the new 10 speed was nice towing my toyhauler at max weight...I was impressed...


And I would not own any of the big 3 diesels out of warranty :laughing:
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Why did you get rid of the Tremor so quickly?
 
DMG said:
Why did you get rid of the Tremor so quickly?
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I bought a 1999 motorhome to tow a jeep and carry my harley.....sold the toyhauler so no need for the tremor.....I traded in myn 19 rubicon and the tremor on a jeep gladiator mohave...turned 2 car payments into one...plan on retiring next December..getting ducks in a row


Tremor rode great and towed nice.....again...I prefer the interior and ease of use of the nav system on the ram over the ford.
 
18 2500hd work truck.

It doesn't pull as hard as 900ft lbs should. You can tell exactly when it goes into regen as the fuel gauge drops.

Buddies tuned and deleted lml will run circles around it and gets the same mileage. He's running the stock pump with a lift pump and after 180k has zero issues other than 2 glow plugs.

I want to get mine deleted, as I think there's about 3-4mpg to recover from the dpf regen. But being a work truck I have a hard time modding anything.

Exhaust brake/turbo brake is awesome. They should have done that years ago.
 
TRINDU said:
CP4 failures aren't limited to just ford Ford. It's common in GM, Jeep/Ram, and VW TDI. There are multiple class action lawsuits. The piston/cam is said to have lubrication issues from ULSD and grinds itself up, sending shavings thus compromising the entire fuel system.

Its prevented by not owning one or swapping to a CP3. Ford just loves to say fuck you, you bought "bad fuel" or put def in the tank. They absolutely refuse to admit its an inherent design flaw. So fuck a 6.7L
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The fuel is one possible cause of the CP4 failures, air getting into the pump is another potential issue and poor filtration is probably the biggest one. Seems that the guys who made sure there was a good positive pressure supply of good filtered fuel didn't have as many issues with the pump as the ones who left them factory. It really came down to the roller flaking on the the piston (looks just like a roller lifter) and the piston not really being positively indexed in it's bore. Once the roller quit rolling it was game over and often the piston would spin in the bore, pumps either locked up or exploded if the metal shavings didn't torch the injectors first. They were also trying to move the same volume of fuel at higher pressures with 2 pistons instead of 3 which put more stress on the whole unit.
 
My buddy just bought a 19 high country with 65k on it for $60k (oof!), and immediately had to put head gaskets on it. He had it a week before he noticed it puking coolant.

Then when they went to start it after the job it wouldn't fire up, they ended up tearing it back down and putting a hpop in it too. Fortunately this was all in warranty, but otherwise was quoted at something like $18k worth of work.
 
Ummduh said:
My buddy just bought a 19 high country with 65k on it for $60k (oof!), and immediately had to put head gaskets on it. He had it a week before he noticed it puking coolant.

Then when they went to start it after the job it wouldn't fire up, they ended up tearing it back down and putting a hpop in it too. Fortunately this was all in warranty, but otherwise was quoted at something like $18k worth of work.
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There's no HPOP on a duramax engine, those were a powerstroke thing as they used high pressure engine oil to actuate the injectors.
 
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