GMC Complaints

The failed component is the engine coolant control valve on a 3.0L Duramax truck. The failure has been documented and confirmed by both an independent mechanic and an authorized dealership. The malfunction creates a significant safety hazard. Without warning, the truck will suddenly enter a reduced engine power mode while traveling at normal highway speeds. When this occurs, the vehicle will not allow acceleration beyond approximately 50 miles per hour. This is especially dangerous when operating on roadways with speed limits of 70+ mph, as the sudden and unexpected loss of power places myself and surrounding motorists at risk. The problem has been reproduced and confirmed by Steele GMC in Round Rock, Texas. In addition, the vehicle has been inspected by an independent mechanic, both of whom verified the coolant control valve failure. Prior to the initial occurrence of the failure, there were no warning signs. Once the malfunction occurred, the check engine light illuminated. General Motors has issued Service Bulletin #25-NA-185 (revised December 4, 2025), which addresses engine coolant control valve failures on 3.0L Duramax vehicles and outlines the proper diagnostic and repair procedures for this exact failure mode. This bulletin applies to 2021–2026 3.0L Duramax trucks. Additionally, GM has implemented Special Coverage program N252508341 for 3.0L Duramax coolant control valve failures, which extends coverage up to 15 years or 150,000 miles when diagnostics confirm the failure condition. Despite the fact that my vehicle’s documented failure matches the exact conditions described in the above-referenced service bulletin and special coverage program, I was informed by Steele GMC that my specific VIN is not included in the warranty. Given the documented safety risk, the confirmed diagnosis, and the existence of official GM guidance addressing this precise issue, I respectfully request this be reviewed and appropriate coverage or corrective action be authorized

Engine lost all power while I was attempting to make a left turn at a very busy intersection. Dash kept saying “check battery”, jump pack did nothing. Engine wouldn’t start.

I get alert saying low oil pressure and the truck turned it's self off and won't start back up. And I got car's and 18 wheelers coming up from behind. They're not paying attention to my emergency lights flashing. It did this twice on me, first time in my neighborhood and the second time on major road with a lot of traffic. I call GMC Corporate office and they know about the Recall on the 2024 GMC Sierra engine cutting off. I was told I need to get a picture or video of the dashboard say low oil pressure and video with me trying to start it back up. I guess I'll have to get hit or kill for them to replace the engine. I have no documentation because I have no picture or video. Didn't know I was supposed to take a picture or video.

UNKNOWN After diagnosis at the GMC dealership they stated that it is same issue as released in the following: Special Coverage Adjustments: N212356540 Front Exhaust Pipe N222385510 Special Coverage Front Exhaust Pipe However they CURRENTLY do not cover our GMC Acadia Model year 2022

The vehicle experienced complete lifter failure on cylinder number 4 bending the intake valve push rod thus shutting down the cylinder. The vehicle has 167,000 miles and is well maintained. The vehicle gave no warning signs that there was a problem. Simply driving down the road, normal engine temperature, normal oil pressure, the check engine light comes on at the same time the engine begins to mis-fire. Pulling over to the side of the road, I could hear lifter noise from the right bank of the engine. The dealership (Ocean Crest Chevrolet/GMC Warrenton, Oregon) confirmed the damage. The mechanic and the service manager both state the damage is a direct result of the GM cylinder deactivation system, and every single one they have repaired has been cylinder number 4. They further stated that GM has recommended a lifter change when repairing the damage, in other words, the lifters that were installed when the engine was originally built are defective. This damage occurs on both the 5.3 and the 6.2 with cylinder deactivation, and according to the dealership, it begins with cylinder number 4. This problem has also been responsible for cam damage which results in total engine replacement/rebuild due to metal contaminating the oil.

1) In May of 2025 I attempted to have the dealership complete the recall which the GM app told me to schedule. Related to the L87 engine failure. According to their own document my engine manufacture date was to be replaced a defective. The dealer told me that there was "no resolution for the issue and turned me away. (see attachments) 2) In June GM changed the procedure adding the PICO test. (see attachment) 3) In October I received the official recall notice and scheduled the test. At the prior service visit I had the dealer give me back the old oil filter. I took it apart and found metal fillings in it. I reported this to the dealer. The truck had the PICO test and passed. They told me that "the filter did its job and the metal in it was normal wear and tear". They replaced the oil cap and filled it with thicker oil. I was sent on my way, told to call if I had any issues. 4) On 2-6-25 while driving 65 MPH on the highway, the engine just shut off without warning. The dash displayed "press start again" while I was traveling at 65MPH. I was able to pull to the side and restart the engine. Service was scheduled and performed on 2-10-26. They found no codes in the computer and could not find the issue. 5) On 2-13-26 while driving 75 on the interstate the engine stopped, the display read "press start again". I was able to coast through traffic and got to the shoulder. After some time and playing with the buttons I was able to get the truck into park. Then I started the engine. I made it off the freeway and onto a side road. I drove a few miles further and stopped for a stop sign. The truck was again dead, displaying "press start again". After several attempts and my vehicle in traffic, I got it to start. It drove for a mile more and the truck was dead. I had it towed to the dealership where they are working in it. It requires a new engine. 6) GM failed and endangered my family while traveling at freeway speeds. They should buy back their failure.

The engine lost power on the Hwy. Resulted in having to tow the vehicle to the dealership for an engine replacement. The truck is a 2024 with only 20K miles. There were no alerts within the interior to make me aware there was a problem. The engineer starting make a knocking sound at the time of failure. I had just gotten off the interstate when it failed. I spoke to a representative at the dealership and they informed me that the same engine will be installed, with a new oil type. I'm writing this given this will diminish the value of the truck, and I have to be worried about the engine failure happening again. Next time it could happen on the interstate with loss of power. I can't trust that to happen.

The contact owns a 2022 GMC Yukon XL. The contact stated that while driving approximately 65 MPH, the vehicle stalled. The failure was a consistent failure. No warning lights were illuminated. The message "Press START Again" was displayed, and the contact restarted the vehicle, and the message "Engine Oil HOT" was displayed on the instrument panel. The contact stated that the vehicle was repaired under an unknown recall prior to the failure to prevent the failure; however, the failure reoccurred. The vehicle was towed back to the dealer to be diagnosed; however, the diagnostic result was pending. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 80,000.

Car flashes "service driver assist system". Took to dealer and they referenced PIT6455 which states GM is still investigating the issue. Truck was returned to me - very concerning to have truck saying driver assist needs to be serviced and GM is unable to service it!

Car was taken in for an oil change at 62k Miles. Dealer advised that it needed a radiator replaced. At 64k miles it was brought into the dealer for warranty work due to a failing thermostat. While being diagnosed, we were told not only the radiator needed to be replaced, but the oil cooler also needed to be replaced. So a 5 year old car with just over 60k Miles had the thermostat/sensor fail and need to be replaced. A radiator fail and need to be replaced and and an oil cooler fail and need to be replaced. Vehicle has been at a GM dealer for all maintenance. No crashes or reasons these parts should fail. Vehicle has never towed anything to but any sort of strain on the cooling system.