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What 61 owners told NHTSA about the 2021 Mercedes-benz GLC Coupe

These are the actual owner complaints behind this car’s reliability verdict, filed with the federal government, unedited. They’re unverified reports, not confirmed defects: read them as leads for your pre-purchase inspection, not a diagnosis.

All (61)Crash / fire / injury (2)Engine (29)Fuel system (11)Lights (10)Electrical system (7)Visibility & wipers (4)Backup camera & sensors (3)Body & structure (3)Driver assistance (3)Transmission & drivetrain (3)Speed control (2)

1 of 61 complaints match · Engine · crash/fire/injury only · clear filters

Aug 7, 2024EngineCrash

The contact owns a 2021 Mercedes Benz GLC 300. The contact stated that while driving at various speeds, the vehicle would lose power and fail to accelerate upon the depression of the accelerator pedal. The check engine light would appear on the instrument panel. Despite the failure, the vehicle would resume normal operation upon restart of the engine. The vehicle was initially taken to a dealer but the dealer could not duplicate the failure. The failure worsened over time which resulted in the contact being rear-ended by another vehicle. The air bags did not deploy upon impact and the contact was not injured. A police report was filed and the contact was able to drive the vehicle away from the scene of the accident. The vehicle was taken to various dealers and independent mechanics where each diagnosed the vehicle with a defective cylinder head. The manufacturer was notified by the dealer about the failure and the manufacturer agree to cover half the cost of the repair. The vehicle had yet to be repaired. The failure mileage was approximately 35,000.

NHTSA ODI 11607115

Working with the data? Download all 61 complaints as CSV · fetched from NHTSA July 20, 2026

How to use these: a complaint is one owner’s report, filed voluntarily and published unverified. Patterns matter more than any single story. If several owners describe the same failure at similar mileage, put that system at the top of your pre-purchase inspection list. Back to the full 2021 Mercedes-benz GLC Coupe verdict →