Chevrolet Suburban loss of power problems

Filed Oct 14, 2026 · Brakes, Engine · MA

On August 7, 2026, while driving a rental vehicle in the Denver, Colorado area with my family, including two young children, the vehicle unexpectedly lost engine power while traveling downhill. The engine shut off, resulting in a significant reduction in brake assistance and creating an extremely dangerous situation. We were able to bring the vehicle to a stop without a collision or injury. After restarting the vehicle, the check-engine light illuminated. The vehicle was no longer considered safe to operate and ultimately required towing by the rental operator. The exact mechanical cause is UNKNOWN. I do not know whether the vehicle was subsequently inspected or repaired by a qualified service center, and I do not have access to its diagnostic or maintenance records. After the incident, I discovered that another renter had reported a substantially similar failure involving the same vehicle approximately one week earlier, including engine problems and a check-engine warning. I have since discovered an additional report of an engine-related issue involving this vehicle after my rental. Despite these recurring reports, the vehicle appears to remain available for rental to the public. I am concerned that this vehicle has a recurring, potentially unresolved defect involving engine shutdown or loss of power while driving. Such a failure creates a serious collision risk, particularly on hills, at highway speeds, or in traffic. I request that the federal safety agency investigate whether this vehicle's repeated failures indicate a broader engine, electrical, or powertrain safety defect. The vehicle remains in the possession or control of the rental operator and may be available for inspection. I can provide supporting documentation of the reported incidents.

Filed Sep 15, 2026 · Engine · IL

Sudden Loss of Power & Shaking: The misfire itself causes a drastic drop in acceleration. If you are merging onto a highway or trying to pass another vehicle, the sudden loss of power can leave you stranded in the path of oncoming traffic. No Stability Assistance: Because StabiliTrak and Traction Control are automatically disabled, the vehicle loses its ability to correct for skids, fishtailing, or hydroplaning. In rain, snow, or emergency swerving maneuvers, a heavy SUV becomes much harder to control. "Limp Mode" (Reduced Power): To prevent the unburned fuel from a misfire from destroying the expensive catalytic converters, the vehicle may force itself into a "Reduced Engine Power" or "Limp" mode. This limits your top speed (often to around 30 mph), which is highly dangerous if you are in the fast lane of a highway. Violent Transmission Shifting: To protect the drivetrain from the erratic power dips of a misfiring engine, the vehicle's computer will maximize transmission fluid pressure. This causes the Suburban to shift gears incredibly hard, which and feel as though the transmission is exploding

Filed Sep 14, 2026 · Engine · FL

I am filing this complaint regarding a serious engine and safety issue with my 2021 Chevrolet Suburban equipped with the GM 6.2L engine, with approximately 45,500 miles. The vehicle has developed a noticeable and abnormal shaking/vibration coming from the engine. At the same time, the vehicle experiences a significant loss of power, at times becoming so severe that the engine feels as though it is going to shut off. This is a serious safety concern. A sudden loss of engine power could occur while driving in traffic, accelerating, merging, or traveling at higher speeds. The vehicle may become unable to accelerate properly or could potentially stall, creating a significant risk of a collision. I am concerned that this issue may be related to a defect affecting GM's 6.2L engines. The fact that this is occurring at approximately 45,500 miles is particularly concerning, as an engine should not experience this type of severe shaking and loss of power under normal operating conditions. I respectfully request that the federal safety agency investigate this issue and determine whether there is a safety-related defect affecting the GM 6.2L engine used in the 2021 Chevrolet Suburban and other GM vehicles. I am reporting this because I believe the sudden loss of power and potential for the engine to shut off could endanger the occupants of the vehicle as well as other motorists

Filed Sep 14, 2026 · Engine · FL

I am filing this complaint regarding a serious engine and safety issue with my 2021 Chevrolet Suburban equipped with the GM 6.2L engine, with approximately 45,500 miles. The vehicle has developed a noticeable and abnormal shaking/vibration coming from the engine. At the same time, the vehicle experiences a significant loss of power, at times becoming so severe that the engine feels as though it is going to shut off. This is a serious safety concern. A sudden loss of engine power could occur while driving in traffic, accelerating, merging, or traveling at higher speeds. The vehicle may become unable to accelerate properly or could potentially stall, creating a significant risk of a collision. I am concerned that this issue may be related to a defect affecting GM's 6.2L engines. The fact that this is occurring at approximately 45,500 miles is particularly concerning, as an engine should not experience this type of severe shaking and loss of power under normal operating conditions. I respectfully request that the federal safety agency investigate this issue and determine whether there is a safety-related defect affecting the GM 6.2L engine used in the 2021 Chevrolet Suburban and other GM vehicles. I am reporting this because I believe the sudden loss of power and potential for the engine to shut off could endanger the occupants of the vehicle as well as other motorists

Filed Sep 14, 2026 · Engine · FL

I am filing this complaint regarding a serious engine and safety issue with my 2021 Chevrolet Suburban equipped with the GM 6.2L engine, with approximately 45,000 miles. The vehicle has developed a noticeable and abnormal shaking/vibration coming from the engine. At the same time, the vehicle experiences a significant loss of power, at times becoming so severe that the engine feels as though it is going to shut off. This is a serious safety concern. A sudden loss of engine power could occur while driving in traffic, accelerating, merging, or traveling at higher speeds. The vehicle may become unable to accelerate properly or could potentially stall, creating a significant risk of a collision. I am concerned that this issue may be related to a defect affecting GM's 6.2L engines. The fact that this is occurring at approximately 45,000 miles is particularly concerning, as an engine should not experience this type of severe shaking and loss of power under normal operating conditions. I respectfully request that the federal safety agency investigate this issue and determine whether there is a safety-related defect affecting the GM 6.2L engine used in the 2021 Chevrolet Suburban and other GM vehicles. I am reporting this because I believe the sudden loss of power and potential for the engine to shut off could endanger the occupants of the vehicle as well as other motorists.

Filed Sep 7, 2026 · Engine · SC

The vehicle experienced an initial incident of significant engine power loss while traveling at highway speeds approximately two weeks prior to the eventual complete engine failure. During that incident, the vehicle unexpectedly lost engine power while traveling at speeds exceeding 65 mph. On Thursday, September 3, 2026, a second incident occurred within approximately one-half mile of leaving my residence. The vehicle again experienced a significant loss of engine power. I had already notified the dealership of the this occurrence and had a scheduled appointment for repairs the following day. I was attempting to drive the vehicle to the dealership as planned. Shortly after leaving my neighborhood, I stopped at a nearby gas station after the vehicle displayed a "Low Oil Pressure" warning on the dashboard. I also subsequently received an email notification from OnStar identifying diagnostic trouble code (DTC) P0016. The vehicle was then driven again and subsequently experienced a catastrophic and complete loss of engine power while traveling at highway speeds above 65 mph. Following this failure, the engine would not turn over or crank and the vehicle could not be restarted. The sequence of events is significant because the vehicle had previously experienced engine power loss at highway speeds, the dealership had been notified of the initial incident, and the vehicle was being driven to the dealership for its scheduled repair appointment when the second power-loss event occurred. The vehicle subsequently suffered complete engine failure. I am documenting these events, including the dates, circumstances, dashboard warning, OnStar diagnostic notification, and sequence of failures, for purposes of establishing the history of the vehicle's mechanical problem and the circumstances leading to the catastrophic engine failure.

Filed Sep 2, 2026 · Electrical, Engine · TX

This problem isn’t just the 6.2L engine. My 22 Suburban has the 5.3L and had engine failure on the freeway going 70 mph in April 2026. Loud noises and loss of power. Towed to dealership and was confirmed that it was the same issues as the 6.2L. The dealership only replaced certain components (gears, rods, camshaft etc.) Parts replaced and vehicle returned a month later but still loss of power and bad idle. New dealership in May 2026, replaced same parts, said faulty parts were used at previous dealership. Vehicle repaired and returned in June2026, a day later new code for service transmission now code thrown and parking break not working. Returned to dealership and said it was a fuel pump module? failed. No vehicle for 3 months and lots of headaches. This recall needs to be extended to the 5.3L engine as well. Needs full replacement, not just repaired. My vehicle still doesn’t run great but Chevy will not honor anymore repairs.

Filed Sep 1, 2026 · Engine · 53,000 miles · WA

The contact owns a 2022 Chevrolet Suburban. The contact received an unknown recall. The contact stated that the vehicle was taken to the dealer, and while parked at the dealer, it was determined that there were metal shavings in the oil and that the engine needed to be replaced. The vehicle was repaired, but a failure occurred 4,000 miles, two months later. The contact stated that while driving 55 MPH, the vehicle lost power and then stalled. The vehicle stopped in the middle of the highway and was inspected. The vehicle was then towed to a different dealer where it was diagnosed and determined that the engine had failed and needed to be replaced. The vehicle was not yet repaired. The vehicle was towed back to the dealer where it was diagnosed and determined that the engine needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure. The failure mileage was approximately 53,000.

Filed Aug 28, 2026 · Engine, Transmission · FL

After having the proper recall performed. The engine locked up while driving on interstate. Total loss of power in heavy traffic nearly causing an accident.

Filed Jul 27, 2026 · Fuel system · 92,709 miles · VA

The contact owns a 2021 Chevrolet Suburban. The contact stated that while driving on the highway, the vehicle experienced reduced engine power and failed to exceed 30 MPH. A message pertaining to the deceleration was displayed. The following Monday, the vehicle failed to exceed 35 MPH, and a friend followed the contact while driving to the dealer. The dealer recommended a fuel filter replacement. The contact declined the repair because the fuel filter life was at 47%; however, the dealer proceeded with the replacement. The contact provided the diagnostic trouble code to an independent mechanic, who informed the contact that the failure was associated with TSB Numbers: 20-NA-197 and 18-NA 361. The contact then advised the dealer of the TSBs, and the dealer determined that the fuel pump module and fuel tank module needed to be replaced. The vehicle was repaired. Additionally, the contact stated that the second-row passenger’s side seat belt buckle failed and was replaced under an extended warranty, although the part was previously replaced under a recall. The manufacturer was notified of the failures several times, but no assistance was provided. The failure mileage was approximately 92,709.