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
2018 GMC Sierra 1500 engine complaints
Page 2 of 4: complaints 11 to 40 of 72, newest first, as owners wrote them.
I have 125,000 miles on my truck. I was traveling with my grandkids in the back seat. We were going through a four way stop. My truck started tapping like a lifter issue. The next thing I know is the truck engine light started flashing and car started to shake. Then, my truck lost all power and a big cloud of blue smoke came out of the tail pipe. The truck could not be driven any further. The symptoms: engine tapping, low oil, engine light flashing, shaking, lost all movement, and a cloud of smoke We had to tow my truck to the dealer and they are still accessing the issue. All symptoms are identical to the current recall of the GMC engines.
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.”
2018 GMC Sierra started having shuddering/jerking/jumping problems at around 60k miles. This problem occurs while driving on straight aways, going uphill and while in drive at a stop sign/light. When the gas is accelerated the truck then hesitates and jerks/jumps. We have taken it to the GMC dealership and paid for the diagnostics and were informed “the problem wasn’t severe enough”. The truck has only been serviced by GMC dealership. So after failed attempts with GMC service department we have taken it to a local small auto shop and they automatically said it was the Drive Train and needed to be taken to a transmission shop. We have been GM owners for decades and are so disappointed in the service received from them.
I purchased a 2018 GMC Sierra 1500 6.2 Denali new. I followed all service requirements including oil changes by GM dealerships. 2025 i noticed my truck power was decreasing. Than I started to hear knocking noses. I took it to a dealership for diagnosis but they couldn't identify anything. Finally it started to skip this is when a dealership diagnose it as being an issue with the active fuel management system. They said my lifters, camshaft, and various other parts was damaged and had to be replaced. Additionally, they said it was a recall on 6.2 engines with the same identical issue but my year wasn't included. The cost to repair approximately 10,000. I really need your attention to this matter! September 10, 2025 my truck placed me and others in danger when it lose engine power. Also my engine light was on for the first time.
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 the federal safety agency 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 federal safety agency 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 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 federal safety agency to report the failure. The vehicle was not yet repaired. The failure mileage was approximately 90,000.
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
2018 GMC Sierra SLT's electric power steering suddenly stopped working, I almost got killed this issue has been reported by other owners
I own a $35,000 2018 gmc Sierra 1500 6.2l V8 4x4 Denali, which is currently down due to engine failure while I was driving down the road.. never had a check engine light on the dash. Haven't had the truck a year before it quit. Rods knocking, crankshaft bearings, loss of power, high rpm with little acceleration. I could have the peddle down to the floor and would barely get to 20 mph.. the motor would jump so bad, you would think it's going to jump out the truck. I have replaced several parts on the truck, including oil pump, filter, solenoid valve sensor, fuel pump, injectors, and sensors, battery, starter a couple times. Did all that replacing for it to get worse and finally quit while driving.. I was stranded in the middle of the road.. IV reported it to the Recall people, but nothing helped. I have taken my vehicle to Express Chevrolet and they did a diagnostic test, which I provided the list they gave me below. When I took it to them, I was using Endurance Warranty, but they denied my claim due to the issues and they didn't cover them. At the time, the motor was still jumping, but smoke was coming out the tailpipe extremely bad, the truck was jerking and jumping. After replacing everything I listed, the truck got worse, started screeching and knocking loudly, loss of engine power, little acceleration. The day the motor quit on me while driving, I got the mph up to about 55-60 and it just quit, and hasn't started back since.
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 federal safety agency Hotline for assistance. The failure mileage was 58,000.
This 2018 GMC Sierra has 100,000 miles on it and in April 2025 the transmission went out and needed a new one. Now in July 2025 the engine has lifter failure leading to the need of a new engine.
I've had the vehicle service twice for the same incident power steering shut off in the middle of drive Vehicle shuts down almost smashed into a freeway wall. This has been to the dealership numerous times to fix it and they have not. We are in the tens of thousands of dollars in repair and still nothing is fixed I've had this vehicle for 5 years it's been In the shop for at least 3 I bought it with 30000 miles it only has 61000 on it right now The last repair lasted 10000 miles this repair only lasted 4000 I almost died and was left Is petrified.
Transmission has a shudder at lower speeds 1200 RMP area. Has been doing it since I bought the truck a few years ago. Took it back for warranty work and they claim this is a very common problem with this transmission. Claim that flushing the system would repair it, which it has not. Occasionally to will almost go out of gear, I have to try getting off the road safely to shut it off. After a few minutes, start it up and it will be back to normal. Also I’m on my 3rd starter. What appears to be another common issue with this model. Sometimes it fires right up, sometimes it’s very weak and others not at all and requires a jump start. All in all, recalls should’ve already been applied to these models. Pay way to much for junk!
The contact owns a 2018 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed and depressing the accelerator pedal, the vehicle failed to accelerate as intended. The message "Reduced Power" was displayed, and the RPMs increased. Additionally, the vehicle jerked, and the contact noticed that there was smoke coming out of the exhaust pipe. The vehicle was driven to the contact's residence. The vehicle was taken to an independent mechanic, where it was diagnosed that the starter, the battery, the fuel pump, the oil pump, the oil pump sensors, and the fuel injectors had failed and needed to be replaced. The vehicle was repaired; however, the failure reoccurred. The contact stated that while driving at an undisclosed speed, the vehicle stalled. There was no warning light illuminated. The vehicle was able to restart; however, the failure recurred. The vehicle was driven to the contact's residence. The vehicle was not repaired. The manufacturer was made aware of the failure, but no assistance was provided. The failure mileage was approximately 133,742.
Engine lifters failed. Heard ticking noise first day truck was purchased that gradually got louder but was told by gmc service shop it was normal to hear the ticking noise. Also when cruise control is on and you are decending a hill the rpms raise and you lose engine compression this will cause your speed to drop to around 20 mph and has happened nunerous times.. as well when making a turn sometimes or just driving the vehicle turns off while in motion and you have to coast to the side of the road and turn the key off and back on to start driving agsin.. the loss of power is a complete blackout no dash.. no engine nothing. As result of the lifter issue the engine also hard shifts in and out of slow gears.. I have not driven my truck in about a year and still owe 22k on it. The issues with this vehicle are the same as the recalled 6.3 v8 engines.
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.
Lifter when bad during engine start up. (known issue)
GM has discontinued a critical engine belt on the 2018 GMC Sierra 1500 5.3L eAssist. This makes the truck undrivable and unsafe to own, even though the vehicle is still under financing and only 7 years old. There is no available part, and no alternative has been offered by the manufacturer.
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.
My engine and all electrical components including power steering and power brakes and all dashboard electrical will fail while driving. It is becoming more frequent and has almost caused an accident on numerous occasions to the point of not being able to drive safely on the highway any longer so now I only stay on surface streets and can't use for any out of town work. I usually do all of my own vehicle maintenance not been able to diagnose the culprit. Unfortunately I'm not able to afford the dealership diagnostic prices but open to any type of inspection.
I have taken it in due to engine mounts 4 different times, transmission replaced and in October 2024 I took it in for issues I was experiencing like I had before my transmission went out. I did not get my truck back until almost Dec 2024 and that was due to there employee backing into the front end of my truck. So after all that my warranty was up Dec 24 2024 and then on April 16th 2025 I was driving my 2018 GMC Sierra 6.2l 1500 Denali 129,600 miles at approx 30 mph it was late so the streets were empty and we started to hear a knocking or what I thought at the time was a very bad exhaust leak. We parked and then we started to try to make it home very slowly which we did and it was not making to much noise. The next day I called GMC and explained they said bring it in. I towed it there to be safe but it did start and still ran at very slow speed. They called me and said that the lift side rockers/ lifters 1 failed and it was stuck due to a misfire and that the engine would need to be rebuilt and sent me over some very vague break down which looked like a lump sum price. I requested and better break down and got a screen shoot and that when he said that’s the best they can do. There were no engine lights on or warnings nothing at all. It also just got serviced at GMC for an oil change on February 27th 2025 along with some air filters. Today is April 29th and still waiting for the service manage to call and see if they can do anything to help out instead of charging full price. I will Attach pictures of the cost break down if possible. Thank you
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.
Lifters failed and damaged engine at 68000 miles
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 the federal safety agency 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)
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.
Lifters and cams fatal failure, requiring extremely pricy replacement of the parts affected or replacement of the entire engine!
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.
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.
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