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.

- Weston, WI, USA

This vehicle has 88400 miles, it out of warranty, which I know this, I use AMSOIL ASM SIG SERIES SYN SAE 0W-20, 5.3L GAS. TWO YEARS AGO, I CHANGED OIL AT RICHARD BUICK GMC IN DAYTON, OH AND SENT A SAMPLE OF THE OIL TO OIL ANALYZERS FOR AN ANALYSIS, THEY SET IT BACK, IT SHOWED THERE WAS A LEVEL 4 SEVERE GASOLINE IN THE OIL. THEY CHANGED THE HIGH SPEEP FULE PUMP, BOTH IN JECTORS, AND IT THOUGHT IT WAS FIXED, ON 12 - 11 -24 HAD THE OIL CHANGED AT LOCAL BOYS SERVICE CENTER, SENT A SAMPLE OF THE OIL-TO-OIL ANALYZERS AND RECIEVED BACK, A SEVERE FUEL LEAK OF GASOLINE IN THE OIL, i DON'T THINK THAT MANY DRIVERS WHO HAVE THIS VEHICLE KNOW ABOUT THIS DANGEROUS PROBLEM, IT COULD CAUSE AN ENGINE FAILURE OR EVEN WORSE, GENERAL MOTORS NEEDS TO FIX THIS PERBLEM.

- Reynoldsburg, OH, USA

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.

- Salem, OR, USA

Engine AFM has failed. No engine light was present at the time. A loud ticking noise was noted from the engine bay. Was taken to get diagnosed, and the AFM was replaced. The problem was then resolved. Transmission has been jerking and hard shifting through the period of owning the vehicle. No diagnosis has been made

- Sunland Park, NM, USA

2018 gmc Seirra 1500 8 speed transmission. Making unsafe conditions while driving transmission tends to make hard shifts, jerks, hesitation when moved into gear, gets worse when stopping momentarily at stop lights and then trying to accelerate vehicle will not move. Makes hard shift and jerks then will accelerate in an unsafe manner.

- Fort Myers, FL, USA

The contact owns a 2018 GMC Sierra LD. The contact stated the vehicle experienced jerking and shaking. The contact also stated when the accelerator pedal was applied, the vehicle made a loud noise and lunged. There were no warning lights illuminated. The vehicle was taken to the dealer where a transmission flush and an alignment were performed. However, the contact stated the failure persisted. The manufacturer was notified of the failure and a complaint was filed. The failure mileage was approximately 30,000.

- San Antonio, TX, USA

My 2018 Sierra began experiencing severe shuddering while driving down the road. The dealer said it was caused by moisture getting into the transmission fluid and contaminating it. In my ownership of dozens of vehicle's this has never happened before. This formerly inexpensive minor fluid change requirement morphed into a $618 major surgery just to fix a problem that should have never occured. If the fluid was contaminated by moisture as the dealer explained, it's a design defect which caused it and nothing I have ever done. I am still unsure as to if the transmission or torque converter may be damaged. The manufacturer should be liable for the cost to fix this not me!

- Sunrise Beach, MO, USA

The electric power steering failed while accelerating into a turn from a stop at an intersection. The wheel was jerked from my hands, and the engine stalled, all electrical failed momentarily. Within a couple of seconds everything returned to normal. This has happened several times since I purchased this vehicle. Also the electrical power steering drops out quite often at low speeds, such as in parking lots. No warnings have ever been given. In May of 2021 the dealer replaced the steering rack, the problem has continued intermittently to this date. I have researched for recalls on this problem and found that GMC issued a recall for years 2014-2017, and am amazed that they could just declare the problem fixed, and leave such a dangerous problem unresolved!

- Palmetto Bay, FL, USA

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.

- Diamond Bar, CA, USA

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.

- Rushville, MO, USA

The contact owns a 2018 GMC Sierra 1500. The contact stated while driving from a complete stop and depressing the accelerator pedal, the engine revved but the vehicle hesitated to respond. There was no warning light illuminated. The contact stated that the failure reoccurred several times. The vehicle was taken to the local dealer, where it was diagnosed that the transmission was slipping and needed to be replaced. The vehicle was repaired. Additionally, the contact stated while driving 60-65 MPH, the vehicle started vibrating and shuddering. The check engine warning light was illuminated. The contact was able to drive to her nearby destination. The vehicle was towed to a second dealer Liberty Chevrolet (105 Cooley Way, Villa Rica, GA 30180) where it was diagnosed that the driver's side lifters had failed and needed to be replaced. The vehicle was repaired; however, the failure reoccurred. The vehicle was towed to a third dealer, Prince Chevrolet Buick GMC of Albany (2701 Ledo Rd, Albany, GA 31707) where it was diagnosed that passenger's side lifters needed to be replaced. Additionally, the dealer diagnosed that the camshaft needed to be replaced. The contact was advised that the warranty would cover a portion of the cost of the repair and she was responsible for the balance. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 84,267.

- Cuthbert, GA, USA

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

- Strafford, MO, USA

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.

- Greenville, NC, USA

While driving 35 miles per hour in the early morning hours I came to a 4-way intersection and applied the brakes slowly. Suddenly, I lost all power in the brakes and the steering wheel locked up. The lights, and stereo remained on, and my dash board display immediately showed a red check engine light. I immediately turn on my hazard lights, turned the ignition key off and tried to restart the truck. There was no clicking sounds. The truck would not start but the lights dimmed and the dash display now showed an intermittent yellow, flickering check engine light. After roughly 30 minutes while waiting for AAA to arrive I tried the ignition key and the truck started up with a red check engine light. Rather than attempting to drive I had AAA tow my vehicle to the Chevrolet dealership where I purchased the truck.

- Eugene, OR, USA

The speed of the truck will not increase. The rpms goes really high and the truck will not move into the next gear. The rear end of truck vibrates. I took this to the dealer and was told it is the transmission fluid is faulty. The check engine light does come on. I did not have the new transmission fluid changed because dealer said is cost $300 for the fluid and $100 for the labor and $168 for the diagnostics. So I still have the same problem. Also told you can not purchase this transmission fluid no where but GMC.

- Tickfaw, LA, USA

Leak detected in the engine oil cooling lines, requiring replacement.

- Denver, CO, USA

I was driving down the highway when my vehicle loss control of operation and check engine light came on. After taking it to the GMC dealership it was determined to be a bad lifter in the motor. The garage had to take the motor completely apart to repair a bent rod and cylinder in the motor. There are numerous reports and a pending class action lawsuit concerning this device in the GMC Sierra trucks and other GMC vehicles. The lifters in the cylinder of this motor are designed to switch the engine from V4 to V6 to save on gasoline. My vehicle has been repaired by the GMC garage but I've seen reports of this problem repeatedly happening in these vehicles and it causes me great concern because if there is a lot of traffic in the area I could get hit or cause an accident by not being able to operate the truck. My vehicle is available for inspection upon request. The safety of myself and others is put at risk because the sudden equipment breakdown could cause an accident. The problem was confirmed by the dealer. No other parties have inspected the vehicle. No warning lamps went off prior to this happening and the vehicle is only a 2018 and only has 36,000 miles on it.

- Albright, WV, USA

47,012 miles radiator failure, leaking badly. GM denied repair under warranty

- Lapeer, MI, USA

The contact owns a 2018 GMC Sierra 1500. The contact stated that the vehicle vibrated abnormally while driving. The vehicle was taken to ingersoll auto of danbury (84 federal rd, danbury, ct 06810, (203)885-7774) for an oil change and the engine was flushed on four occasions. The contact stated that the vibration increased. The vehicle was taken to the same dealer and a tire rotation and alignment was performed. The contact was also informed that the tires needed to be replaced. The torque converter was also replaced however, the failure remained. The manufacturer was made aware of the failure and referred the contact to NHTSA for assistance. The approximate failure mileage was 47,000.

- Monroe, CT, USA

At 55000 miles the radiator started too leak GM would only pay $250 dollars of the $876 it cost

- So. Deerfield, MA, USA