2021 Mercedes-Benz GLC 300: hesitation when accelerating

Filed Jan 8, 2026 · Engine, Transmission · CA

Vehicle Information: Year: 2021 Make: Mercedes-Benz Model: GLC 300 Engine: M264 Mileage at time of failure: Approximately 65,000 miles Complaint Description: While driving, my 2021 Mercedes-Benz GLC 300 began experiencing repeated engine misfires and rough running, accompanied by a persistent check engine light. These symptoms began shortly after I purchased the vehicle and progressively worsened over time. The vehicle exhibited reduced engine performance and hesitation while driving. The condition was intermittent at first but became more frequent, indicating a progressive mechanical issue rather than a sudden failure. At approximately 65,000 miles, the vehicle was evaluated by an authorized Mercedes-Benz dealership and diagnosed with a catastrophic cylinder head failure, requiring full cylinder head replacement. The estimated repair cost is approximately $8,000. The vehicle has never been modified and has not undergone prior engine repairs. The failure occurred well before what would be considered normal wear for an engine component of this type. Based on the progression of symptoms, the dealer diagnosis, and similar reports from other owners of the same model and engine, this appears to be a systemic defect involving the cylinder head and valve train, rather than an isolated incident or maintenance-related issue. This condition presents a potential safety concern due to loss of engine performance, drivability issues, and the risk of reduced power while operating the vehicle.

Filed Nov 12, 2025 · Engine · VA

There is a hesitation in or "shuddering" that causes the car to go into limp mode while in operation. I was in traffic and the car just powered down and would not get up to and or maintain speed. I contacted the local dealership and was told that there are other models and or engines in this car that have this issue and that they actually have a recall on this issue. The dealership noted that they have 1 or more that require this exact repair on every single week. The dealer told me what was wrong with it by the code it threw... He didn't have any hesitation because he is so familiar with this issue. The warning lights came on after the car powered decreased... there was no "pre" warning that this was going to happen.

Filed Oct 17, 2024 · Engine · 56,000 miles · MO

The contact owns a 2021 Mercedes Benz GLC300. The contact stated that while driving at a low speed, the vehicle began to shake as the check engine light appeared on the instrument. In addition, the contact stated that the vehicle began to hesitate upon the depression of the accelerator pedal. Due to the failure, the vehicle was towed to a dealer where the vehicle remained in the dealer's possession for weeks. The contact was later informed that the engine cylinder cap was defective and needed to be replaced. The vehicle was then towed to an independent mechanic where it remained in their possession and had yet to be repaired. The manufacturer was notified of the failure and referred the contact to the federal safety agency Hotline to file a complaint. The failure mileage was approximately 56,600

Filed Jan 12, 2024 · Engine · SC

On 12/17/2023 at approximately 6:00 am while traveling to a friends house, my car stalled out on me. The engine light came on and the car started hesitating ( sputtering) and then shut off. I tried to start the car and it did with the engine light still on. I called a tow truck and had it towed to Carlton Mercedes. On 12/18/2023 the service advisor contacted me via text to say they will do a diagnostic to find the problem and will be in touch. 5 days later, i was told that the sensors were wet due to standing rain water I encountered and that nothing else was wrong. I picked up the car later that evening. 3weeks later the same exact thing happened. The car started sputtering (hesitating) the engine light came on and it shut off. Although my VIN number was not apart of a recent recall for my make and model, I would like the Safety Department to investigate the issue and have my car added to the recall list. The recall address the issue of loss of power to vehicles of the same make and model as mine. The Mercedes Manufacture will not fix my car under the recall if it hasn't been added to the list. I don't believe the consumer should have to pay simply because the VIN was added to the list even thought the problem exist. Please Help!

Filed Sep 3, 2021 · Acceleration, Engine · 7,000 miles · AR

The contact owns a 2021 Mercedes-Benz GLC300. The contact stated while driving at various speeds, the vehicle hesitated to accelerate while the accelerator pedal was depressed. The contact stated there was no warning light illuminated. The vehicle was taken to a local dealer but was not diagnosed or repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 7,000.