2019 GMC SIERRA 1500 Complaints

Transmission blew on a 7 year old vehicle. Was replaced entirely and is NOW having the EXACT SAME PROBLEM AGAIN!

The contact owns a 2019 GMC Sierra 1500. The contact stated that the trailer lights flashed intermittently while the vehicle is turned off. Additionally, the contact stated while driving with a trailer hitched to the vehicle, the messages "Trailer Disconnected" and "Trailer Connected" were intermittently displayed, and the running and marking lights were inoperative. The contact related the failure to GM TSB Numbers: 20-NA-198 (Trailer Running Lights Shut Off Due to Excessive Load on the Running Lamp Circuit), PIT5747B (Diagnostic Tip - Trailer Lighting Complaints with Trailering App RPO U1D) and N192213550 (Service UpdateTrailer Integration Module Software Error). The vehicle was taken to an independent mechanic, where it was determined that the failures were due to a wiring or software failure. The contact was informed that the failure was a factory defect because the fuses were in good condition. The vehicle was not repaired. The dealer and the manufacturer were not contacted yet. The failure mileage was approximately 64,000.

While driving, the vehicle suddenly began running rough, losing power, and displaying engine warning lights. Due to the severity of the issue, the vehicle was towed to a GMC dealership for diagnosis. The dealership diagnosed lifter failure and a cracked cylinder head. The dealership also documented coolant intrusion, oil/coolant contamination, and evidence of internal engine damage. Repairs were attempted, including replacement of the cylinder head and lifter. After the repairs were completed, the vehicle never left the dealership because it continued misfiring on the same cylinder. GM later determined the engine had a failed piston ring and scored engine block requiring complete engine replacement. The vehicle has approximately 55,000 miles, has been properly maintained, and was purchased new. This catastrophic engine failure resulted in loss of power and major internal engine damage at relatively low mileage. I also opened a case directly with GM Customer Assistance regarding this failure. The case involved multiple escalations after the initial repair attempt failed and the vehicle ultimately required full engine replacement. GM ultimately advised that only partial assistance toward the engine replacement would be provided, leaving the customer responsible for a significant portion of the repair cost. I am submitting this complaint because this vehicle appears consistent with the ongoing NHTSA investigation involving GM 6.2L L87 engine failures and loss of motive power.

The contact owns a 2019 GMC Sierra LD 1500. The contact stated that while driving approximately 65 mph, the vehicle, went into low power mode, and was able to move safely to a and then the vehicle stalled. The vehicle was towed to an independent mechanic and was diagnosed as the engine has no compression, suspect a possible crankshaft failure, also a possible engine replacement. The manufacturer was notified of of the failure. The contact associated the failure with NHTSA Campaign Number 25V274000 (Engine and Engine Cooling). The approximate failure mileage was 130,000.

After the vehicle was purchased in October 2023, it immediately had an issue shifting very hard. After numerous trips to the servicing dealership in attempts for error codes to be discovered with no success, the dealership gave the recommendation to flush the transmission as this was a fix for this type of engine in November 2024. The transmission was completely flushed in November 2024. The vehicle continued to have the issue with hard shifting and also developed less efficient gas mileage and would misfire upon ignition and there was a constant knock when running. After a prominent ticking began in May 2026, it was discovered that the timing chain was broken and we were told the rods could impale the engine and go through the hood if the engine was not replaced. The engine had completely failed and needed to be replaced including radiator and hoses. The engine, radiator, and hoses were replaced 05/2026. The invoices for both of these Service transactions are attached. After much research and advice, it appears this issue was the same issue that was happening with the other 6.2L L87 engines from the years 2021 to 2024 that were recalled.

Engine component failure. If not identified early could have caused catastrophic failure being disabled in traffic. This problem has been diagnosed and confirmed by a certified GM dealership. Initial warning sign was a knock in the engine, no warning lamps. First identified on 9/2/25 at 80,345 miles. Dealership changed oil to a higher viscosity. Problem gradually got worse, diagnosed #3 cam lobe failed 3/9/26 at 85,437 miles.

I was driving my 2019 GMC and all of a sudden I pulled into a subdivision the vehicle shut off and would not start again. I wasn't given an y warning or heard any sounds it shut off and would not start up again. I checked the battery and it was fine. I had it towed to a mechanic shop. They replaced the starter, and the battery module. after that they ran codes and the codes were P00C6 and P0340. I had it towed the the local chevrolet dealership and they told me I needed to have the engine replaced, however they don't have any engines available or know when they would be able to get one.

I was on my way home from work and everything was driving fine and then I got 1/4 mile from my house and the motor started making a very loud grinding sound. I could barely accelerate. The issue happened out of nowhere. No issues prior to this happening. I was driving about 40 miles an hour when the issue started and I limped it to my driveway, luckily I was not very far away. I have a 3 month old baby and this was my reliable family vehicle. Who’s to say what could have happened if I was driving at a higher speed with my child in the car. When it happened it started shaking really bad. I checked everything that I could. It sounded like my motor was starving for oil. I decided to go ahead and change my oil to see if that could have been the issue. I had just changed the oil approximately 2000 miles before this. I changed the oil and filter. Went to start it up and still same very loud grinding sound, shut it back off and have not started it since cause I’m afraid to damage it further. I checked the oil that I drained out of it and looks like small metal flakes in the oil. No warning prior to this happening. Just out of no where it sounds and felt like my motor was going to blow.

The contact owns a 2019 GMC Sierra. The contact stated that while driving at 20 MPH, the check engine light began to flash. The driver pulled over. The vehicle was knocking. The contact stated that failure was due to premature engine failure. The vehicle was towed to the local dealer, where it was diagnosed with a cylinder 3 lifter malfunction. The vehicle had misfired. The vehicle was not repaired. The manufacturer was notified, but no assistance was provided. The failure mileage was approximately 77,000.

The 2019 vehicle experienced a significant engine failure consistent with widely reported issues involving GM 6.2L V8 engines in GMC Sierra and Chevrolet Silverado platforms. Prior to failure, the vehicle developed abnormal engine noise including ticking/knocking sounds, followed by loss of engine performance and mechanical failure. Vehicle diagnosis indicated internal engine damage requiring major repair or full engine replacement. The failure occurred despite normal maintenance and relatively low mileage for a modern full-size truck. The vehicle had no prior abuse, modification, or racing use. Based on technician feedback from December 2025 service call and publicly reported incidents, the failure appears consistent with commonly reported GM 6.2L issues involving: connecting rod bearing failure crankshaft/bottom-end damage lifter or valvetrain failure internal metal contamination sudden engine seizure or loss of propulsion This issue presents a serious safety concern because sudden engine failure can occur during normal roadway operation, potentially resulting in: sudden loss of power inability to accelerate vehicle shutdown while driving increased crash risk in traffic conditions I am aware of numerous similar complaints involving GM 6.2L V8 engines across multiple model years, including investigations and recalls affecting related vehicles and powertrains. My vehicle appears to exhibit the same or substantially similar failure characteristics. I request that NHTSA continue investigation into 2019 model-year GMC Sierra 6.2L engine failures and evaluate whether these earlier vehicles should be included in broader recall or warranty coverage.