Community Forums

millsrv · 11-02-2022, 11:15 AM

I am not suggesting that there is any problem(s) with the 2017 to current L5P Durmax Engines. I am curious owning a 2021 L5P myself if anyone has had any serious issues with this engine.
In doing research I find problems like NOX Sensors, DEF heaters / tanks, and injector electrical plugs, but that is about it.
Please let us know what your experience has been if you own a L5P equipped GM truck. I am not interested in opinions, or something you might have heard, only your experience as an owner. Thank you!

BirchyBoy · 11-02-2022, 12:24 PM

Mine has been very reliable and 90% of its life is short in-town trips. I did replace a temperature sensor at the suggestion of owners on a Duramax site, and I have an Edge CTS monitor I use to keep track of temps, etc. I have no complaints yet.

Seymour2Lane · 11-02-2022, 12:37 PM

I purchased a new 2022 Denali 2500 diesel in March which now has 4600 miles.
No issues.
I love this truck!

BirchyBoy · 11-02-2022, 02:18 PM

Quote:

Originally Posted by BirchyBoy

Mine has been very reliable and 90% of its life is short in-town trips. I did replace a temperature sensor at the suggestion of owners on a Duramax site, and I have an Edge CTS monitor I use to keep track of temps, etc. I have no complaints yet.

This is the part I replaced. When I replaced it at 36k the little cage around the sensor was gone.

GM ACDelco Original Equipment 12681993 Intake Air Pressure and Temperature Sensor https://a.co/d/g6KlnkF

Brentw · 11-02-2022, 07:21 PM

Map sensor failure due to not using a winter front. Injector connector failure, cylinder #4, that caused a quite a ruckus.

xc-mark · 03-16-2023, 03:56 PM

The L5P motor seams to be one of the most reliable Duramax's I have owned. They are work horses don't treat it like a 1/2 ton work it will last and get the job done fairly easy. Some guys buy these trucks as a daily driver and never work them and may not know how to maintain them.

the 2020 and early 21 trucks had a DEF tank heater issue that was fixed with a reflash and possible a tank heater and harness ( the connector burned up 2 pins at the tank ) . Mine has been fine now 2 winters since the repair by GM.

DEF , if your not working the truck your going to have a system with possible problems of clogged DEF injector.