2020 Mercedes-Benz GLC-Class Powertrain & Transmission Problems

My 2020 Mercedes-Benz GLC 300 triggered check engine light with code P06DA (engine oil pressure control) at 40,000 miles. The failed component is an oil pressure control sensor/solenoid worth approximately $200. However, due to Mercedes-Benz's engine design (M264 engine), the entire engine must be removed from the vehicle to access and replace this part. Repair estimate from authorized Mercedes-Benz dealership (Mercedes-Benz of Stevens Creek): $8,391. SAFETY CONCERN: Loss of oil pressure can cause catastrophic engine failure while driving. Engine seizure at highway speeds poses serious risk of loss of vehicle control, potential accident, and harm to occupants and other drivers. This is a known, widespread design defect affecting Mercedes-Benz vehicles equipped with M264/M274 engines across multiple model lines: GLC 300 (2019-2023) C 300 (2019-2023) E 300 (2019-2023) GLC 43 AMG, C 43 AMG GLB 250, A 220, CLA 250 Mercedes-Benz's own authorized dealership confirmed they are "seeing this issue more and more." Despite awareness of this widespread defect, Mercedes-Benz has not issued a recall or Technical Service Bulletin. The design makes repair financially prohibitive ($8,000+), meaning many owners continue driving with compromised oil pressure — creating an ongoing safety hazard on public roads. Mercedes-Benz refused to repair under goodwill, then denied repurchase after 30-day review. They have left consumers with no remedy for a known safety-related design defect. I am requesting NHTSA investigate this as a safety defect affecting potentially hundreds of thousands of vehicles.

I have had my car for almost two years. This problem has been on-going the whole time. It happens intermittently, I never know. I will be driving it and usually when I am making a turn or pulling onto a main road, you press the gas to go and the car hesitates and makes a loud brooooooooom sound like it is trying to go or figure out what to do and if you are pulling out onto a main road with on comming traffic, this is dangerous. We have seen information that on the 2019 and 2018 GLC300's this has been documented, my car is a 2020 but it's the same thing. It's like the car hesitates and slows down when it should go!

Winning noise in rear end. We bought used noticed noise getting loader. Took vehicle to dealer. We were informed the rear Differential was bad and would have to be replaced. Vehicle has 61,198 miles on it. Wife drives car around town and on trips out of town. i was told they would have to get replacement form Germany. around $9,088. Dealership has helped with splitting cost $4,544.00. After checking around seems the Mercedes is having some problems with this part. When i escalated to Customer care at MB it took (4) phone calls from me to finally get a response from them. We affeered you half off and nothing there is nothing more we are going to do. But keep receipt incase a recalled happens?? Case # 03071039 (1-800-367-6372). This part should not be something that goes bad on a 2020 with 61,981 miles. Any help would be appreciated!!

The contact owns a 2020 Mercedes-Benz GLC63. The contact stated that while his wife was driving at highway speeds, the vehicle inadvertently decelerated while the accelerator pedal was being depressed. The check engine warning light illuminated, and a message displayed on the instrument panel stated that the “Transmission Needs to Cool, Stop and Pull Over Immediately”. The contact stated that the vehicle had locked in first gear and decelerated to approximately 55 MPH. Additionally, the contact stated that his wife was able to navigate the vehicle back to the residence. The contact stated that the following day the contact was able to restart the vehicle. The vehicle was taken to the dealer where it remained awaiting a diagnostic test. The vehicle had not yet been repaired. The manufacturer was notified of the failure and the contact was provided a case number. The failure mileage was approximately 24,000.

It took a few minutes to be able to completely turn left out of a shopping center while waiting in line. When finally able to turn left, the car stalled into what appeared to be neutral where I had no control to increase speed and was turning very slowly. Oncoming traffic from both ways were coming and luckily stopped on-time. I had to turn off the entire car and restart in the middle of the road in order to be able to drive again. There could've been a massive collision if cars were not paying attention on both sides. Note that the car was NOT in neutral at the time and was in drive the entire time. This same incident also happened over a year ago but thought it was something I could've done wrong or was a one-time thing. Now that it's happened twice confirms that there is something wrong with the car. The car did not indicate a power failure or warning lights during this incident. I have an appointment with Mercedes on 4/25 to get this looked at. This has been reported on other models from other car owners but we have never seen a recall. This is a serious malfunction and could've gotten myself or others killed. I do not feel safe driving this car unless it is fixed.

THIS VEHICLE IS UNSAFE. WHEN DRIVING IN TRAFFIC THE ENGINE/TRANSMISSION WILL NOT DELIVER POWER IN RESPONSE TO THROTTLE APPLICATION, IT IS ALSO INCONSISTENT IN IT'S RESPONSE FROM ONE TIME TO THE NEXT. THE VEHICLE WILL HESITATE FOR UP TO 4-5 SECONDS BEFORE RESPONDING TO THROTTLE COMMANDS WHEN PULLING OUT INTO TRAFFIC. THIS IS MOST NOTICEABLE WHILE ROLLING BETWEEN 5-10 MPH AND APPLYING POWER ALSO WHILE MAKING A SHARP TURN. THE POWERTRAIN ALSO IS EXTREMELY INCONSISTENT IN IT'S RESPONSE WHICH MAKES PULLING INTO TRAFFIC EXTREMELY DANGEROUS. I SUSPECT THE PROBLEM STEMS FROM SENSORS IN THE ELECTRONIC STABILITY PROGRAM (MB ESP), THE TRANSMISSION MODULE AND THE FLY BY WIRE THROTTLE AND ENGINE CONTROL MODULE. PROGRAMING OF SHIFTS OF THE TRANSMISSION SEEM TO FIGHTING WITHIN THE TRANSMISSION ITSELF. ALL OF THIS ADDS UP TO AN EXTREMELY DANGEROUS SITUATION WHEN DRIVING IN TRAFFIC. I HAVE TAKEN THE VEHICLE BACK TO THE SELLING DEALER (MERCEDES BENZ OF NORTH PALM BEACH FLORIDA) TWICE ONLY TO BE TOLD THAT THIS IS NORMAL. I FILED A REQUEST WITH MERCEDES BENZ OF NORTH AMERICA TO BUY THE CAR BACK WITHOUT SUCCESS.