GMC Complaints

Engine started making clicking noises at highway speed.the vehicle lost power and was difficult to start. The 2024 gmc sierra was driven three blocks the a GM dealership and it was determined that the engine had failed. It took two months to complete the repair by replacing the engine with a rebuilt one

My vehicle is making a knocking sound and has the L87 6.2 V8 engine that is under recall for catastrophic failure. It has been evaluated by 2 mechanics that say it needs a new engine. Yes it is available for inspection upon request. Although it has not shutdown yet, both mechanics have said it is eventually going to be a catastrophic failure. My safety and families safety is at risk of it shuts down and causes an accident. There is no warning light currently displayed.

I pulled up to a local store and parked. Just as I was getting out I saw smoke coming from the upper seatbelt area of the rear drivers side seat inside the cab. I jumped in back to see if there was a fire. As I was trying to pull out the top cushions of the interior roof, trying to locate a possible fire, the rear driver-side window suddenly "exploded" - broke in a web pattern across the entire window. I then broke out the center of the glass in case a fire started. I could smell a burning scent. The, suddenly the rear passenger-side window exploded in the same web pattern across that entire window. When my wife arrived to pick me up she could also smell the scent of burning wire. After researching the internet for this issue, we found out that this is a known issue. We discovered at least 6 websites describing this exact issue - one being a GM Customer Satisfaction Program #N192265660 dated January 2020. Apparently the component that has been determined to have failed is the rear window defrost (particularly in models with an electronic sliding rear center window) overheats and causes the smoke and the window breakage. After our truck being at the dealership for approximately 1 month while GMAC supposedly researched the issue, we received word today verbally (Aug 27, 2026) that they declare this issue is not a manufacturer's defect, and they will not cover the repairs. We have requested written confirmation and haven't yet received it. Not only do we currently have the original warranty on this vehicle, we also purchased the extended warranty for the vehicle. The vehicle was inspected by the dealership from which we purchased the vehicle and they stated they couldn't find any issue that would create the damages that the vehicle incurred. Prior to the incident there were no warning lamps or symptoms of any problem.

Once we learned about the 6.2L Engine Failure we took the vehicle to Mckinney GMC in [XXX], test were run and were told the engine needed to be replaced, but would take several months to repair. We could not wait months for the vehicle so we had the vehicle towed to Sewell GMC in [XXX] (we bought the vehicle CPO from there) they ran test and said we didn't need a new engine but that they would just replace the oil weight and it would be fine. The engine has not run right since, it shakes and idles hard, and was never given a clear answer as to how metal shavings were found in the oil at McKinney GMC but magically disappeared at the Sewell dealership. Its very unsettling that at any moment while driving the engine could seize and blow. I feel like we have a lemon vehicle and the oil weight change is simply a band aid for this situation. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

This vehicle has been towed into GMC service 3 times to date. #1. 2/2024 (mil 22,662) would not start, low voltage msg, replaced battery. #2. 4/2026 (mil 57,854) vehicle went into N on its own while I was driving down the road, msg on dash "function not available", I stopped and the engine died & would not restart, no engagement from starter motor, found P0615 present, found blown fuse on battery distribution fuse block, replaced. #3. 7/2026 (mil 63,041) vehicle went into N on its own while I was driving down interstate, msg on dash "function not available", I stopped, the engine died and would not restart, found main battery fuse blown, engine seized, found spun rod bearing full of metal debris, replaced engine, radiator, cooler lines, seals, gaskets, bolts, & fluids. My safety was at risk as I was driving down a highway and the interstate 2 of the times the vehicle put itself in N. The problem has been confirmed by the dealer. The vehicle has been inspected by the dealer's service dept. Prior to these incidents I did not notice any symptoms that would have alerted me of what was to come. **This report is referring to my latest incident which was engine seizure. *Two recalls have been performed, #1. 5/2025 "reprogrammed serial data module" & #2. 11/2025 "engine loss of propulsion recall", replaced oil with 0W-40 & "ECM software update recall", replaced ECM with SPS.

The Dynamic Fuel Management (DFS) is causing damage to lifters, valves, camshafts, and connecting rods. I received a recall notice from GMC on the GMC app, stating "L88" Engine loss of Propulsion or Related field action: Special coverage N252494003. The connecting rod and/or crankshaft engine components have manufacturing defects that can lead to engine damage and engine failure. My 22' GMC 1500 has just over 30k miles, and issues are starting with the previously mentioned engine parts. A "pico" test was completed at approx 20k miles. Too early and not enough mileage to show the true damage caused by the "DFM" Dynamic Fuel Management.

The Exhaust Pressure Differential Sensor Pipe (boost pipe) blew off while towing a heavy trailer uphill on a busy interstate. I had to cross 3 lanes of traffic to get as far as possible off the road. The truck was sent into limp mode and would barely crawl. Our lives were put at risk of being hit by the many tractor trailers traveling that highway, or another driver traveling at high speeds. The truck was eventually towed to the nearest GM dealer for service. The pipe was replaced, but the faulty one was not kept on hand. The repair was not covered by GM. The extended warranty covered the pipe repair only, with out of pocket still being over $400. There were no warning lights on the dash until after the pipe blew off and the truck was thrown into limp mode. This is a known problem with these diesel engines, for years, yet nothing has been done by GM to fix the problem. Owners are replacing with aftermarket parts because the factory parts won't hold up. This damaged the DPF and DEF system as a result. The replacement parts are listed in my owners manual under the 5 year/100000 mile powertrain warranty, yet the claim was denied by GM. There are forum after forum with these failures for the past 15 15 years or more, yet nothing has been done to fix the problem and owners are put at risk of injury or death. When the dealer replaced the part, it was disposed of so no inspection could be made by anyone else to determine if it was defective.

My 2023 GMC Yukon AT4 with the 6.2L V8 has experienced multiple serious engine-related failures. The original engine previously was making a whining / knocking noise, then seized and required complete engine replacement under a GM recall/campaign involving 6.2L engine failures. The replacement engine later developed a lifter/valvetrain failure and required lifter replacement. The vehicle is now again exhibiting a pronounced rhythmic mechanical knocking/tapping noise, primarily during cold starts after sitting for an extended period. The noise occurs on most cold starts and has been documented in multiple videos. The vehicle is currently at a GMC dealership for inspection. I provided the dealer with several videos clearly demonstrating the noise. The dealer has stated that it has not yet been able to reproduce the condition and is attempting additional cold-start testing. The exact cause is currently UNKNOWN. No consistent warning lights or dashboard messages have appeared with the current knocking condition. My concern is that this vehicle has already experienced a catastrophic engine seizure, followed by internal valvetrain/lifter failure in the replacement engine, and is now again exhibiting abnormal mechanical engine noise. I am concerned this may indicate another developing internal engine failure that could potentially result in engine seizure or sudden loss of power while driving, including at highway speeds or in traffic. The vehicle and engine remain available for inspection, and multiple video recordings of the recurring cold-start knocking are available.

My Shift To Park senor come on often and wouldn't let me turn the vehicle off. I have taken to dealership for repair. Long wait and because parts are back ordered due to numerous vehicles having this same problem. This has left me stranded in my vehicle and not able to turn it off and leave the vehicle. I feel this is unsafe and should be handled on a recall. I am now without a vehicle for who knows how long?

The car stalled while traveling down a road. We tried to restart and it would run for a few seconds and stall. We could not restart. There were no warning lights before the stall and after the engine would not run to get any other indicators that something was wrong. Had it towed to dealership, their diagnostic's showed it was a fuel pump driver module. Upon researching the issue, there is a recall for this problem but my VIN was not included in the recall.