2022 Mercedes-Benz GLC 300: engine failure

Filed Aug 8, 2026 · Engine, Fuel system · NY

My 2022 Mercedes-Benz GLC 300 (17,700 total miles) suffered a catastrophic structural engine block failure and an explosive loss of propulsion while driving at highway speeds. This occurred exactly 6 days and 183 miles after a franchised Mercedes-Benz dealership performed the official fuel pump impeller safety recall (the federal safety agency Campaign 23V‑445).The dealership's official repair invoice documents that the technician custom-modified the recall remedy by reusing parts, explicitly stating: 'Relocated floater from old pump onto new fuel pump.' Simultaneously with the mechanical engine failure, a 'Reduce Engine Oil Level' message flashed on the dashboard, indicating severe fuel dilution from the compromised fuel system.The dealership is actively violating federal recall mandates by refusing to investigate this failed safety remedy unless I sign an open-ended financial check for a diagnostic and teardown fee. They have also revoked my substitute transportation to coerce payment. Mercedes-Benz USA Corporate Case Number 23652724 has been opened. I am requesting a federal safety investigation into this dealer's non-compliant recall remedy execution."

Filed Jul 3, 2026 · Brakes, Electrical · IN

While driving down a busy neighborhood street 2 lanes with cars on both sides making it a 1 lane road pulled over to the side a little to let cars pass. All of a sudden ALL electrical and engine stopped and turned off. Only thing that was powered was instrument cluster with multiple warnings like SRS Malfunction, Steering Malfunction, SOS Inoperative, Parking Brake and more. We believe the car had also shifted to park on its own. No power to anything not even hazard lights. Nothing electrical had any sort of power. Could not even turn car off completely could not get the instrument cluster to turn off with ignition button. When I say everything electrical had no power I mean everything except instrument cluster. Hazard lights power locks, lights of any kind, ignition switch, gear selector, windows, sos feature, nothing had power. I could not imagine having this issue driving on the interstate and having the car completely loose ALL electrical power and what could happen to specially with a SRS malfunction and issue with steering. Had to have a wrecker come with wheel dollys because car could not be put in neutral and towed to Mercedes dealer. Upon their inspection they found the Circuit 30T relay to be stuck in the open position which killed power to everything so the technician replaced the engine compartment pre-fuse panel. It is such a unsafe and very hazardous issue to have a relay failure to where all power is lost especially if you were driving on interstate especially at night with traffic to loose everything electrical even hazard lights and headlights, SRS maltunction, Steering. Mercedes needs to figure this very unsafe issue out.

Filed Aug 25, 2025 · Transmission · 51,519 miles · OR

The contact owns a 2022 Mercedes-Benz GLC300. The contact stated that while driving 60 MPH, the accelerator pedal was depressed; however, the vehicle failed to accelerate as intended. The contact stated that there were several unknown warning lights illuminated before the engine seized. The vehicle was restarted; however, while driving at an undisclosed speed, the failure reoccurred. The contact started the vehicle again, and the vehicle was slowly driven to the residence. The vehicle was not diagnosed or repaired by an independent mechanic or the dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 51,519.

Filed Aug 3, 2025 · Engine, Transmission · CA

Defect Summary: Since 2024, my 2022 Mercedes-Benz GLC300 has had a persistent, abnormal engine noise consistent with the sound of a 4-cylinder diesel engine, despite being gasoline-powered. The noise occurs both while idling and in motion. On several occasions, the coolant warning light illuminated while the noise persisted. The defect has worsened over time, becoming louder and more frequent. Events & Safety Risks: The dealership repeatedly claimed “no problem found” because no warning lights appeared and no scanner codes were present, ignoring my time-stamped video evidence. At one point, I was advised to drive the vehicle from Morgan Hill, CA to the dealership while making the loud noise for diagnostics — an unsafe recommendation. When the coolant warning light appeared, the service department planned only to top off coolant. I insisted on a diagnostic, which revealed a coolant hose leak. Driving with a leak could cause overheating and sudden engine failure, creating a serious safety hazard for myself, my child, and other motorists. Repair History: Multiple visits to Mercedes-Benz of San Jose (2024–2025) for the same defect. Each time, the defect was dismissed or not resolved. No meaningful repairs were performed. The issue persists today. Evidence: Time-stamped video proof of defect, full service records, and documentation of correspondence with the dealership are available. Safety Concern: This unresolved defect creates a risk of sudden engine failure or overheating while driving, potentially causing loss of control or stranding occupants in unsafe conditions.

Filed Sep 6, 2024 · Transmission · 20,370 miles · IL

The contact owns a 2022 Mercedes-Benz GLC300. The contact stated while driving 76 MPH, the accelerator pedal was depressed; however, the vehicle failed to accelerate as intended. The contact stated that the vehicle speed independently decelerated. The contact safely drove the vehicle to the shoulder of the road. The contact stated that a warning light illuminated indicating do not shift the gear, contact the dealer. In addition, the contact stated that the gear shifter seized, and the wheels locked up. The contact stated that the failure occurred while driving on a major highway. The vehicle was towed to the dealer. The vehicle was not diagnosed or repaired by an independent mechanic or the dealer. The contact stated that the vehicle was serviced at the dealer in July 2024. The contact stated that several unknown repairs were completed. The manufacturer was not made aware of the failure. The failure mileage was approximately 20,370.