2027 3.0 l Duramax

Sparky134 · June 14

Will the the engine be engineered to solve the problems plaguing the 2019-2026 Engines?

newdude · June 14

54 minutes ago, Sparky134 said:

Will the the engine be engineered to solve the problems plaguing the 2019-2026 Engines?

What problems?

Atlas · June 14

55 minutes ago, newdude said:

\What problems?

Just a guess based on the mentions I've seen on this forum...

Failing coolant control valves (LM2, LZ0)

No start / long crank issues (LM2)

Thrust bearing failures (LZ0)

Timing chain failures (LM2)

Fingers crossed GM has more revisions and updates in the work because the 3.0 is awesome (when it can be trusted).

newdude · June 15

1 hour ago, Atlas said:

Just a guess based on the mentions I've seen on this forum...

Failing coolant control valves (LM2, LZ0)

No start / long crank issues (LM2)

Thrust bearing failures (LZ0)

Timing chain failures (LM2)

Fingers crossed GM has more revisions and updates in the work because the 3.0 is awesome (when it can be trusted).

...was looking to see what the 3 post OP had to say since they've got a personal issue here and 3 different threads they made within the same time period...just today....and then regurgitating that some owners on facebook and other forums have issues which is a small number out of total ownership of 3.0 Duramaxes.

Edited June 15 by newdude

silveradosid · June 15

i would say it is someone who bought a deisel and shouldn't have, they arenot meant to put around town or excessive idling. the brake thing is a gm problem, some do worse and some do bettter. i put 140k on my 2014 and was expecting the same on the 2020 but only got half of that mileage. a2020 with40k is not that many miles, my 2020 has 120k

Edited June 15 by silveradosid

Jus Cruisin · June 27

I'll be buying another 3.0l when I replace my 2025 Sierra. I had an issue (engine siezed) but it was replaced and has been fine ever since. I'm spoiled with the excellent fuel economy to swap to a 6 2l or its replacement.

Coastie05 · June 27

One can only hope that they will correct or have already corrected the issue.

Sparky134 · June 29

On 6/14/2026 at 6:38 PM, newdude said:

Thrust bearing, turbo oil filter….What problems?

jl6690506 · 2026-07-08T08:59:54Z

On 2026/6/15 at AM5点43分, Sparky134 said:

该发动机的设计能否解决 2019-2026 年款发动机所面临的问题？

It's too early to say. The 2027 3.0L Duramax is based on the LZ0 engine with ongoing improvements, but there's no evidence yet that it has completely resolved all the issues seen in the 2019–2026 models.

diyer2 · 2026-07-08T15:56:50Z

I would only own a diesel if I towed regularly.

newdude · 2026-07-09T15:49:55Z

On 6/29/2026 at 11:56 AM, Sparky134 said:

Thrust bearing is a very small window. But nice try.

Turbo oil filter? Haven't seen any failures. Change your oil more frequently. Use a better oil than the factory oil.

Jake87 · 2026-07-09T18:54:08Z

On 6/14/2026 at 7:38 PM, Atlas said:

Just a guess based on the mentions I've seen on this forum...

Failing coolant control valves (LM2, LZ0)

No start / long crank issues (LM2)

Thrust bearing failures (LZ0)

Timing chain failures (LM2)

Fingers crossed GM has more revisions and updates in the work because the 3.0 is awesome (when it can be trusted).

For the long cranking, I do know this engine is very susceptible to fuel quality. Watch your centene values and bio content. This isn't a Jimmy that will run off of crude.

Atlas · 2026-07-09T19:05:40Z

12 minutes ago, Jake87 said:

For the long cranking, I do know this engine is very susceptible to fuel quality. Watch your centene values and bio content. This isn't a Jimmy that will run off of crude.

Our local stations' (basically everywhere) diesel fuel has the minimum required cetane and is up to 20% biodiesel, ULSD. *My* truck runs fine on it. (When I'm not dumping the local choke-and-puke's used fry oil in the tank to save money!) - kidding.

I'm not sure the documented long crank issues with some of these engines is fuel related, but fuel can certainly always be suspect. Always good to consider bad fuel as a possible cause.

Edited 1 hour ago by Atlas

PunchT37 · 2026-07-09T19:41:39Z

35 minutes ago, Atlas said:

Our local stations' (basically everywhere) diesel fuel has the minimum required cetane and is up to 20% biodiesel, ULSD. *My* truck runs fine on it. (When I'm not dumping the local choke-and-puke's used fry oil in the tank to save money!) - kidding.

I'm not sure the documented long crank issues with some of these engines is fuel related, but fuel can certainly always be suspect. Always good to consider bad fuel as a possible cause.

I got a flashback to Smokey and the Bandit.