2018 GMC Sierra 1500 Engine

Engine failure. 6.2l with AFM system Extreme oil consumption Heavy metal in oil Loud ticking 120789 miles Purchase date 05/29/2025 Madras, Oregon Chevrolet Dealer

The lifters in my engine collapsed. This caused a push rod to be bent and the cam shaft to be damaged causing thousands to fix. While I was driving. I could feel the engine malfunction causing my speed to significantly decrease. The vehicle was fixed through an independent mechanic. Mechanic stated that the active fuel management system is the cause for the lifter collapse. There was no warning before the failure

The injector failure in my 2018 GMC Sierra 1500 resulted in repeated misfire conditions (P0300 and P0307), causing the vehicle to lose power unexpectedly while driving. The engine would hesitate, shake, and struggle to accelerate, especially during merging or highway speeds. These symptoms created a significant safety hazard because the vehicle could not reliably maintain speed or respond to throttle input. Sudden power loss in traffic exposes the driver and surrounding motorists to an increased risk of collision, particularly during lane changes, freeway merging, intersection crossings, and passing maneuvers. The dealership confirmed internal injector failure, and the vehicle has been out of service for three months without resolution. This is a safety-critical defect that compromises vehicle controllability, stability, and safe operation on public roads.”

The contact owns a 2018 GMC Sierra 1500. The contact stated that while driving at various speeds, there was an abnormal banging sound coming from the vehicle. There was no warning light illuminated. The contact inspected fluids but found no defects with the vehicle. The vehicle was then taken to an independent mechanic, where the mechanic discovered that the lifters and cam shaft were defective. Due to the failure, the engine was replaced. The contact stated that recently, the abnormal tapping sound returned. The vehicle was taken back to the independent mechanic, who confirmed that the failure with the lifters had returned. The vehicle was taken to a dealer who confirmed the lifter failure, and the contact was provided an estimate for the repair. The manufacturer was notified of the failure, and the contact was provided a case number. The contact was then referred to the NHTSA to report the failure. The vehicle was not yet repaired. The failure mileage was approximately 90,000.

Lifters failed and damaged engine at 68000 miles

The contact owns a 2018 GMC Sierra 1500. The contact stated that while attempting to accelerate from a stoplight, the vehicle hesitated before accelerating. A day later, the failure reoccurred, and the RPMs increased before the vehicle accelerated. There were no warning lights illuminated. The vehicle was taken to the dealer, who diagnosed that the connecting rod had failed, and there were metal shavings inside the engine. The contact was informed that the engine needed to be replaced. The contact related the failure to NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the VIN was not included. The vehicle was not repaired. The manufacturer was informed of the failure and confirmed that there was no recall on the VIN. The manufacturer opened a case for the failure. The manufacturer referred the contact to the NHTSA Hotline to report the failure. The failure mileage was approximately 169,000.

The contact owns a 2018 GMC Sierra 1500. The contact stated that while driving on a neighborhood road at 40 MPH, the check engine warning light was flashing with an abnormal knocking sound coming from the engine, and the vehicle was vibrating abnormally. The contact pulled over and used a diagnostic scanner to perform a diagnostic test on the vehicle. The scanner retrieved DTC: P0301 (Cylinder #1 Misfire). The vehicle was towed to a local dealer to be diagnosed, and the contact was informed that the lifters, pushrods, camshaft, sparkplugs, and oil pump were faulty and needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 111,000.

The contact owns a 2018 GMC Sierra 1500. The contact stated while his mother was driving 75 MPH on the highway, there was a popping and ticking sound coming from the engine, and while depressing the accelerator pedal the vehicle failed to respond. The driver was able to pull over to the right side of the road and waited for tow truck assistance. A dealer was not contacted. The vehicle was towed the dealer and was diagnosed and determined that the engine needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure, and informed the contact engine would take a while to be ordered. The contact was referred to the NHTSA Hotline for assistance. The failure mileage was 58,000.

Radiator cracked along outer edges. Similar to previous TSB’s as released by GM, but my vehicle doesn’t fall under the years covered by that TSB

I have a 2018 GMC Sierra 1500 with a 6.2 motor. Back in December of 2024, I had to replace a tie rod, cam shaft, and the lifters. $8400 to get everything replaced. Since my warranty had expired, I had to pay all of this out of pocket. I know there is currently an investigation going on in GMC's 6.2 motors. Almost 900,000 engine failures. This is unacceptable. GMC just needs to man up and send out the recall notice. Since I have already had to pay for my replacements, GMC should do the right thing and and cut me a check.

Lifter when bad during engine start up. (known issue)

Lifters and cams fatal failure, requiring extremely pricy replacement of the parts affected or replacement of the entire engine!

The contact owns a 2018 GMC Sierra 1500. The contact stated that at start-up there was an abnormal ticking sound coming from the engine. There were no warning lights illuminated. The local dealer was contacted; however, the vehicle was not diagnosed. The contact was informed that the vehicle was out of warranty, and that the VIN was not under recall. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 17,000.

My vehicle was a well maintained 2018 GMC Sierra 1500. It has 58000 miles. I was driving in 30 mph zone thank God. Heard a loud boom and the truck lost power and shut off. I got out and oil was pouring out. I took it to the GMC dealership and they told me the engine failed. They didn’t know why or what caused the failure. But said they is a hole in the block and all they can say is something in the engine failed.

DRIVING 70 MPH ON [XXX] IN MODERATE TRAFFIC WHEN MY VEHICLE SUDDENLY SLOWED DRAMATICALLY AND BEGAN TO SHUDDER . I WAS IN THE MIDDLE LANE OF THREE WESTBOUND MARKED LANES AND WAS ALMOST HIT BY A DRIVER BEHIND ME WHICH HAD BEEN FOLLOWING TOO CLOSELY. THE CHECK ENGINE AND TRACTION CONTROL LIGHT CAME ON AND MY OIL GAUGE WENT TO THE HIGH SIDE. I EXITED ONTO [XXX] AND AT 40 MPH THE TRUCK WOULD SHAKE AND SHUDDER UNTIL I DROVE THE 6 MILES TO MY RESIDENCE. ON [XXX], I HAD THE VEHICLE TOWED TO LASH GMC DEALERSHIP IN JOHNSTOWN OHIO. ONCE THERE THE VEHICLE WAS DIAGNOSED WITH A FAILED LIFTER THAT BROKE INTO PIECES RESULTING IN A BENT ROD AND DAMAGED CAM SHAFT. THE DEALER RECOMMENDED FULL ENGINE REPLACEMENT DUE THE SEVERITY OF THE FAILURE. THE TRUCK IS A 2018 GMC SIERRA DENALI WITH ONLY 65,449 MILES ON IT. IT COST ALMOST $70,000.00 NEW AND THE REPLACEMENT ENGINE COST ME $14,221.96. I FEEL MY PERSONAL SAFETY WAS JEOPARDIZED IN THIS INCIDENT. SINCE THAT TIME I HAVE RESEARCHED THE 6.2 GMC ENGINE ONLINE AND HAVE FOUND REPORTS OF NUMEROUS SIMILIAR FAILURES AND INCIDENTS INVOLVING THE ENGINE IN QUESTION. I TRULY FEEL NHTSA SHOULD TAKE A STRONG LOOK AT THE ENGINE FAILURES INVOLVING THIS ENGINE AND FORCE GMC TO REPAIR OR REPLACE THE ENGINES IN QUESTION DUE TO THE SAFETY ISSUES INVOLVING THE ENGINES FAILURES IN TRAFFIC AND THE RISK ASSOCIATED WITH AN OCCURENCE. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

My 2018 Silverado 1500 has had 3 cylinder 4 misfires over a 9 month period that had to be repaired after warranty. This caused the repair/replacement of the lifters. I have had this happen for a forth time this year January 7 2025 with the same code of "cylinder 4 misfire". That means four of the same issues in one year. I can be driving along smoothly, then suddenly from one light to the next, the check engine light comes on with the misfire to cylinder 4 coming on. It was shared with me the AFM can cause this to happen. On the third time of misfire, I saw a little smoke, then once it was repaired with lifters replaced, no smoke and back to running smoothly. This time the intake cam lobe was scored which voided the warranty. I am now at a crossroad as to what to do now, and have parked the truck for now. It is my understanding the 5.3L engine was considered a solid engine until the AFM was installed. Did I mention this is the first "truck" I have ever owned? I have had a Chevrolet vehicle since I was able to drive, and have never had engine problems of this magnitude. My concern now is that this could cause my engine to lock up while I'm driving around and cause a possible accident. I depend on this truck as my mode of transportation, but now I have to make a decision that impacts me greatly as a senior citizen on a fixed income.

The failure was a lifter collapsed in my vehicle's motor. I had reduced power and major shuttering due to the issue. If I had been towing a load I would have possibly become a hazard by not maintaining a speed that would have been able to keep up with traffic flow. Also if I had been in an congested traffic area I would have been slower to clear or have major breakdown causing increased backups. It was confirmed by a local shop. There were no warning lights at the time of incident, nor leading up to this incident. Fortunately no accidents or disruptions happened and I had to be towed in to a repair shop.

Engine failed before 100,000 miles. Lifter failed leading to a damaged camshaft and replacement of lifters being require. Required 10,000$ in repairs. Failure light appeared suddenly. No issues were known of ahead of incident.

Spun main bearing in motor. Motor blown. It is available for inspection. GM mechanic inspected and quoted for new motor. Vehicle shut down going down interstate at 78 mph. No warning.

The contact owns a 2018 GMC Sierra 1500. The contact stated that after starting the vehicle, there was an abnormal ticking sound coming from engine compartment. The vehicle was taken to the local dealer who diagnosed that the exhaust manifold bolts had fractured and needed to be replaced. The vehicle was not yet repaired. The manufacturer was not yet notified of the failure. The failure mileage was 64,000.

Vehicle is a 2018 GMC Sierra Crewcab 4x4 with a 5.3 engine. The vehicle was purchased new in Washington and serviced at the Chevrolet dealership in Oregon within vehicle recommended service intervals. At 64K miles, the engine developed a sudden AFM lifter issue. Lifter for cylinder #6 came apart causing the engine to miss, smoke, have excessive oil on the spark plug, and low cylinder PSI (75 compared to others at 200+). Vehicle is just outside of it's 5 yr/60K powertrain warranty. Vehicle is undrivable and will need probable engine replacement due to damage from AFM lifter failure. My mechanic verified the miss, oil on the spark plug, and low PSI. The local Chevy dealership removed the valve cover, inspected, and advised that the lifter came apart. Dealership wants $1200 to pull the head to determine extent of damage and $4-5K to repair valves or $12-14K for engine replacement. GM offers no assistance at this point.

I am told by a GMC dealer that my engine mount is cracked/worn and needs replacing otherwise the engine can fall out. My mechanic tells me this is a common problem with GMC trucks; specifically the driver’s side engine mount. Perhaps a recall is necessary if this is a common issue. My vehicle is a 2018, so only 5 years old.

When I’m towing my small boat, my temperature gauge starts to rise on my engine and there are no warning lights and it has caused me to have to pull over. I have told the dealership about this. Everyone seem to act like it’s no big deal but when I’m having to pull over, because I’m afraid my motors getting too hot, it’s a problem. And not only that even when I’m not towing anything my temperature gauge keeps going up then back down up and then back down never in my life have I experienced a vehicle doing this

The contact owns a 2018 GMC Sierra 1500. The contact stated that while turning left at an undisclosed speed, the vehicle lost motive power. No warning light was illuminated. The contact was able to restart the vehicle; however, the failure recurred. The vehicle was taken to the dealer; however, the dealer was unable to duplicate the failure. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 72,000.

Radiator failed. Mileage is under 60k. It is currently being replaced by dealership. Dealer Representative noted that it is a fairly regular occurrence for these models. So much so that the dealership stocks this replacement radiator(hard for me to understand). There was no indicator lights to alert to this malfunction, it was noticed after work one afternoon when coolant was dripping out of the front of the vehicle.