2019 GMC Sierra 1500: misfire or rough idle

Filed Sep 16, 2026 · Engine · 159,000 miles · CO

The contact owns a 2019 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle came to a full stop to allow wildlife to cross the road. Upon accelerating, the engine made an abnormal banging noise. The contact stopped to inspect the vehicle and observed an engine misfire while idling. The vehicle was towed to the residence, where an independent mechanic diagnosed that the lifters had collapsed, and that the engine needed to be disassembled for further diagnostic testing. The failure mileage was approximately 159,000.

Filed Jun 30, 2026 · Engine, Fuel system · NY

Lifters (the part that opens and closes engine valves) fail prematurely. There was a loud ticking noises, rough idling. Took to dealership and they advise that yes the lifters are failing and not drivable at this time.

Filed Jun 11, 2026 · Engine · FL

On May 27, 2026, I was on my way home from work when I went to accelerate the vehicle and all the sudden it started shaking and the check engine light came on with the EBS. I was able to get the vehicle to a repair shop local the next day, who took the car apart. What was thought to be an easy fix of spark plugs and fuel injector, became even more after they put back together and the cylinder was still misfiring. After several hours of taking apart the engine, the mechanic determined that the hydraulic valve lifters had failed. This has been an ongoing issue with with the 5.8L V8. Due to a recall not being under the vin yet, i have now incured a $16k expense to add an engine to it after i purchased it in Nov of 25 at $97,000. This is a saftey issue and luckily no one was hurt when the car started shaking and couldn't go over a certain speed. I want this reviewed and looked at for possible reimbursement as there have been several other vehicles with the same known issue.

Filed Jun 9, 2026 · Engine · AZ

While towing Jetski's the #2 Cylinder has a persistent misfire. Was able to limp to Chapman Chevrolet where it took 2 days to diagnose. Vehicle is below 70K, which just recieved a brand new transmission and torque converter due to metal shavings from converter getting pushed through to the transmission. Service Advisor's Message below: "Performed further diagnosis and requested engine teardown to determine root cause of misfire. During disassembly, found cylinder #2 intake/exhaust valve train failure, including a bent pushrod and a severely scored/collapsed lifter. Inspection revealed the damaged lifter had caused abnormal contact with the camshaft lobe, resulting in significant scoring and wear of the camshaft. The failed lifter and bent pushrod led to loss of proper valve operation and cylinder misfire. Point of failure is lifter #2 that resulted in camshaft failure as consequence. I am in the process of generating a quote and taking pictures for the extended warranty." Seems like another AFM/DFM issue has brought down another GM Motor. Why are these motors not part of the recall, when they are going down the same was as the recall? My safety and my family were put at risk for a possible catastrophic failure and loss of power due to the engine being faulty. There were no warning laps, just Check engine Light, Parking Break Wrench Light. The only other sign was a quite tick that is with most Chevy/GM Motors.

Filed May 27, 2026 · Engine, Fuel system · VA

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 the federal safety agency investigation involving GM 6.2L L87 engine failures and loss of motive power.

Filed May 21, 2026 · Engine · SD

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.

Filed May 11, 2026 · Engine · 77,000 miles · FL

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.

Filed Apr 24, 2026 · Engine, Steering · IA

driving and truck started to misfire (due to collapsed lifter after shop diagnosis) that then made my truck do reduced steering assist and my wheel got super hard to turn that almost sent me in the ditch at 60MPH and also turned off my Electronic Stability Control and also turned on my Service Parking Brake drove straight to the shop and parked it very lucky i did not crash and the fact that multiple people this has happend too GM need to recall from the 2019 and up for these lifters after reading about it.

Filed Mar 13, 2026 · Engine, Fuel system · WA

While driving down the highway experienced a partial loss of engine power causing jerky/rough operation, harsh shifting, and unpredictable behavior. Was told by the dealer service manager that it was likely a misfire in one of the cylinders. After diagnostics and servicing that included changing spark plugs, wires, and a full engine service it was later confirmed to most likely be due to a stuck lifter and will require a complete engine replacement. I have subsequently learned that this is a common problem with this L87 engine and may be an early indicator of failing crank bearings associated with a recall for later model years of my same vehicle. Seems to me that recall ought to be expanded to include earlier models with L87 engines.

Filed Feb 18, 2026 · Engine · CT

Engine loss of power many different engine code took it to the dealership. Now they say lifters, rockers are loose and worn,broken,the cylinder 5 misfire, engine needs rebuild at 88,000 miles. Dealer wants over ten thousand dollars to take apart and repair

Filed Jan 23, 2026 · Engine, Fuel system · IL

My vehicle recently experienced a sudden flashing check engine light, severe misfiring, and rough engine operation, creating an unsafe driving condition. An inspection by an authorized GMC dealership, Serra Buick GMC Champaign, confirmed a failed deactivating valve lifter on Cylinder 5, documenting that the lifter ceased movement after a single engine rotation. The dealership advised that the failure necessitates replacement of all lifters and extensive internal engine components, at an estimated cost of $5,650.75. This defect is not isolated, unforeseeable, or the result of consumer misuse. It is directly associated with General Motors’ Active Fuel Management (AFM) system, which has been widely reported to cause: •Premature lifter collapse •Camshaft damage •Severe engine misfires •Loss of power while driving •Catastrophic engine failure

Filed Jan 9, 2026 · Engine · 71,799 miles · IN

The contact owns a 2019 GMC Sierra 1500. The contact stated that while driving 75 MPH, the vehicle failed to accelerate as intended while depressing the accelerator pedal. There was an abnormal sound coming from the engine. No warning lights were illuminated. The contact stated that on a separate occasion, while driving at an undisclosed speed, blue and white smoke was coming from under the hood. The contact pulled over to the side of the road, and the smoke ceased. The contact opened the hood and inspected the engine. The contact restarted the vehicle, and the smoke started coming from under the hood again. The messages "Parking Brake Service Required”, “Reduced Steering Assist”, “Proceed with Caution" were displayed, and the check engine warning light was illuminated. The contact stated that while driving and coming to a stop, the engine jerked abnormally. The vehicle was taken to an independent mechanic, where it was diagnosed with oil intrusion into the spark plugs with a misfire in cylinder #6, and the piston rings were fractured, and there were scratches on the cylinder walls. The vehicle was not repaired. The contact stated that the failure persisted. The manufacturer was made aware of the issue. The contact was referred to the dealer for assistance. However, the contact was concerned about the damage to the engine and feared driving the vehicle. The vehicle was not taken to the dealer. The failure mileage was 71,799.