2018 GMC Sierra 1500

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.

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.

Noted the rear sliding window did not work. Upon further research and investigation found fuse 2 in the drivers side fuse box popped. Replaced the fuse and did not solve the problem. Further investigation found the harness that controls the rear sliding window and other items was sheared (all 3 wires cut in half). The harness is routed from the inside of the center console, through the drivers side hinge (pinch point where it cut the harness, and to the backside of the center console. Spliced the wires and reconnected confirming the fix to the problem. This issue poses a fire hazard. Recommend a recall to reroute the harness or a form of corrugation to better protect the harness and prevent further issues.

The contact owns a 2018 GMC Sierra 1500. The contact stated that while driving at 45 MPH, the vehicle began to shudder, and he decreased the speed. The contact drove to his residence. The next day the vehicle was driving as expected until it became hot and began to shudder again. The transmission was not shifting as designed. The contact checked underneath the vehicle but failed to locate an issue with the transmission. The rear differential was hot and burned his fingers, but medical attention was not provided. The vehicle was taken to the local dealer, where it was diagnosed that the torque converter and transmission needed to be replaced. The vehicle was not repaired. The manufacturer was contacted, but no additional assistance was provided. The failure mileage was approximately 22,000.

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.

The contact owns a 2018 GMC Sierra 1500. The contact stated that the vehicle failed to shift into gear as needed. The vehicle was taken to the dealer, where the contact was informed that an unknown part was loose. The vehicle was repaired. Additionally, the contact stated that while driving at various speeds, there was an abnormally loud sound coming from underneath the vehicle near the transmission. The vehicle was taken to the dealer, where the contact was informed that no failure was found. The contact stated that while driving 55 MPH, the vehicle started to decelerate unintentionally. The contact stated that there was smoke coming from the brake pedal. The contact pulled over to the side of the road and allowed the vehicle to cool down however, the brakes locked up unexpectedly. The vehicle was driven to the dealer to be diagnosed. The dealer informed the contact that the braking system had failed and needed to be replaced. The vehicle was repaired; however, the failure persisted. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 72,000.

The contact owns a 2018 GMC Sierra 1500. The contact stated while driving 70 MPH, the vehicle started shaking violently, prompting the contact to pull over to the shoulder of the roadway. The vehicle returned to normal functionality, but upon the contact continuing to drive to his destination, the failure reoccurred. The contact stated that the RPM rapidly increased and the temperature gauge began to indicate that the engine was overheating. No warning lights were illuminated. The vehicle was taken to an independent mechanic, who diagnosed a failure with the auxiliary transmission oil cooler line, resulting in damages to the transmission. The contact was informed that the transmission needed to be replaced. The vehicle was not repaired. After investigating the failure, the contact related the failure to Special Coverage Adjustment: N182188930. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was 131,000.

The contact owns a 2018 GMC Sierra 1500. The contact stated that while driving approximately 28 - 35 MPH, the vehicle started shaking abnormally. There were no warning lights illuminated. The contact continued driving cautiously. The vehicle was taken to the dealer to be diagnosed and it was determined that the torque converter had failed and needed to be replaced. The vehicle had not been repaired. The contact stated that the torque converter had been replaced twice with the first replacement performed at approximately 27,000. The manufacturer was made aware of the failure. The manufacturer had referred the contact to the NHTSA Hotline to report the failure. The failure mileage was 66,000.