2020 MERCEDES-BENZ GLC 300 Complaints

On Saturday October 5th at roughly 8:30 p.m. heading West on I-94 near battle creek, MI, the glass sunroof on our Mercedes suddenly exploded out and shattered. We were traveling at 75 mph with little surrounding traffic and no over-head obstructions. It took a second to re-gain control of the situation and slow down to a stop. We had the sun-shade closed, saving us from glass shards raining down from the exploded sunroof. The following Monday morning, Oct 7th around 9:00 a.m., we called Mercedes about the issue. They were indifferent and offered no assistance. They pointed out that our MY2020 with 29,711 miles on the odo was not covered under warranty for the sunroof shattering and that we would have to deal with our insurance company. They also informed us that they would not have any rental cars available during a repair until at least December. We mentioned that there was signs on the internet of class-actions against Mercedes for similar sunglass explosions to which they quickly responded with - not on MY20 300 GLC. We did get the sunroof replaced through our insurance. Anecdotely, when we took it into the glass repair shop, they had just did another one, similar situation the week before. This could have been tragic. Glass shards could have been everywhere. The only reason the sunscreen was deployed was that we had our baby granddaughter in the car only 1 hour earlier. Otherwise, that screen would have been open and the glass would have rained down on everyone in the car.

SRS malfunction warning displayed on vehicles dashboard. Vehicle was diagnosed and displayed code B009749 Indicating: the crash sensor on the right hand side has a malfunction. There is an internal electrical fault.

The contact's son owns a 2020 Mercedes-Benz GLC300. The contact stated that when the vehicle was taken for the State Emissions Inspection, the vehicle failed the inspection due to a defective "smoke cannister". The contact stated that after the vehicle failed the inspection, the "check emissions" message appeared on the instrument panel. The contact called a dealer and was advised to purchase and install the smoke cannister. The vehicle was taken to an independent mechanic who installed a new smoke canister; however, the failure reoccurred, and the vehicle failed the State Emissions Inspection test again. The vehicle was taken back to the dealer where the vehicle was diagnosed with a defective smoke canister and valve. The vehicle was not repaired. The manufacturer was informed of the failure. The failure mileage was unknown.

The contact owns a 2020 Mercedes-Benz GLC300 equipped with Goodyear Tires, Tire Line: Eagle Sport All Season, Tire Size: 255/45/R20, DOT Number: NE12JU1R1021. The contact stated that within a year of purchasing the vehicle brand new, he noticed that there was significant amount of rubber coming off the outer side of the front passenger's side tire. The contact stated that the failure was moderate on the front driver's side tire. The contact stated that the vehicle was taken to the dealer, where the front driver's side tire was replaced twice due to the failure. Additionally, the front passenger's side tire was replaced three times; however, the failure persisted. The contact stated that upon investigating the failure online, he learned that the steering knuckle might be damaging the tires. The dealer was notified of the failure. The vehicle was not diagnosed or repaired. The vehicle and the tire failure mileage were approximately 6,000.

Engine began unpredictably running rough. Would lose ability to accelerate, in traffic. Engine light came on. Originally took to dealership, computer indicated a “misfire cylinder 2” was told by mechanic at dealership it was possibly “bad gas” and they cleared all codes. Continued to get worse. Took vehicle to a licensed “Mercedes Doctor” mechanic who had to replace cylinder head to correct. Vehicle is now running better than new!

The contact owns a 2020 Mercedes-Benz GLC300. The contact stated while driving at an undisclosed speed during a rainstorm, the contact became aware that there was water inside the headlight assembly. Later, the contact stated that while driving at night, the headlamps were not functioning as needed. The contact stated that after a visual inspection, the driver’s and passenger’s side indicators were not functioning. The headlamp warning light was illuminated. The vehicle was taken to an independent mechanic, who diagnosed a failure with the headlight assembly. The vehicle was not repaired. The manufacturer was notified of the failure but provided no assistance. The failure mileage was 65,000.

The contact owns a 2020 Mercedes-Benz GLC300. The contact stated that while driving at an undisclosed speed, the engine misfired. In addition, the check engine warning light was illuminated. The contact was turned off and restarted the vehicle. The contact stated that the vehicle drove as needed. The contact stated that the vehicle was taken to an independent mechanic however, the failure was unable to be duplicated. The vehicle was not repaired. The contact stated that the failure occurred intermittently for several months. The vehicle was taken back to the independent mechanic where it was diagnosed with a failed engine vent seat and the engine vent seat needed to be replaced. The vehicle was not repaired. The contact was advised to take the vehicle to the dealer. The vehicle was taken to the dealer where it was diagnosed with a failed engine vent seat and the engine vent seat needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and a case was filed. The failure mileage was approximately 25,000.

Engine failure needs cylinder head replaced which is very common amongst this car. Same make and model is covered under warranty but mine has a different engine that isn't covered. These cars were made during covid and have faulty parts.

the power steering wheel adjustment stopped working, leaving the steering wheel stuck in a very unconfutable position for driving. The car just ended its 4 yr warranty

Center COMAND screen malfunctions. No rear camera view when reversing when screen does not work. Dealer attempted a repair but issue remains. Parts ordered for replacement.