2021 Mercedes-Benz GLC Common Problems & Defect Telemetry
Authoritative defect intelligence synthesized from 61 verified NHTSA owner complaints, 0 federal safety recalls, and interquartile failure mileage telemetry.
The 2021 Mercedes-Benz GLC receives a 8.1/10 MazicBay Reliability Index based on 61 verified NHTSA federal complaints and 0 safety recalls. The primary reported failure mode is Engine Stalling, Oil Consumption & Cooling Defect Reports with a median failure point at 40,500 miles (IQR: 34,897 – 59,250 mi). Out-of-warranty repairs benchmark at $950 – $3,200 .
11.1 complaints / 10k sold
Verified US federal records
Crash, fire & stall audit
0 Active / Free Remedies
Top Reported Problem Clusters (7)
Engine Stalling, Oil Consumption & Cooling Defect Reports
- Engine sudden stall / hesitation while driving
- Abnormal oil burning / consumption
- Check Engine Light (MIL) flashing
- Engine overheating / coolant loss
“While driving in my neighborhood at 25 MPH, my Mercedes GLC300 suddenly lost power and the check engine light illuminated. My car would no longer exceed 25-30 MPH, but I drove it straight to the dealership and they said it was a faulty cylinder head and will cost $10,000 to fi...”
“Getting P06DA trouble code meaning that there is something wrong with the oil pressure solenoid in the oil sump. this is a known issue where the wiring of the solenoid get frayed. cost of repair for the (cheap part) is $7,500 because of 18 hour labor involved. MB knows this is...”
“The engine starts shaking, smell of gas car than stops while driving, could caused an accident and severely injured someone on the freeway. This is a major safety issue after further researching this particular issue MB of Canada issue a warranty letter extension for this part...”
Electrical Parasitic Drain, Infotainment & Harness Reports
- Unexplained battery drain after sitting overnight
- Infotainment display / instrument cluster blackouts
- Accessory malfunction / alternator fault warnings
“Getting P06DA trouble code meaning that there is something wrong with the oil pressure solenoid in the oil sump. this is a known issue where the wiring of the solenoid get frayed. cost of repair for the (cheap part) is $7,500 because of 18 hour labor involved. MB knows this is...”
“The contact owns a 2021 Mercedes-Benz GLC300. The contact stated that the rear-view camera was not functioning properly. After restarting the vehicle, the camera operated as needed; however, several days later, the camera became inoperable. The contact referenced NHTSA Campaig...”
“This is a well-known issue with these engines. See TSB (Service Bulletin) The 2021 Mercedes-Benz GLC 300 has 42,000 miles and the warranty ran out 2 weeks ago. The vehicle is up-to-date on service. Fault code P06DA00 Engine Oil Pressure Control Circuit/Open. The Yellow Check E...”
Fuel Pump Pressure Loss & Fuel Delivery Defect Reports
- Sudden loss of propulsion power at highway speeds
- Extended engine cranking / failure to restart
- Fuel odor near fuel tank / engine bay
“High beam can't auto dim Fuel pump fail to operate, misfires, and shut down while driving”
“The contact owns a 2021 Mercedes-Benz GLC300. The contact stated that while driving at low speeds, the vehicle lost motive power struggling to produce enough power to propel itself on a slight incline. The check engine warning light was illuminated. The vehicle was taken to an...”
“Vehicle has a known engine failure. Leaking valve in Cylinder head. Cylinder 3 injector is faulty”
Transmission Hesitation, Hard Shifting & Slipping Reports
- Hard gear shifts / delayed engagement into Drive/Reverse
- Transmission shudder / jerking under acceleration
- Transmission slipping between gears
“The engine starts shaking, smell of gas car than stops while driving, could caused an accident and severely injured someone on the freeway. This is a major safety issue after further researching this particular issue MB of Canada issue a warranty letter extension for this part...”
“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...”
“Car has experienced rough idling, sluggish to no acceleration, check engine light illuminates and no shifting of gears regardless of speed. It appears to be going into limp mode. This has occurred monthly for the last four months. After pulling over, the car is turned off, wai...”
Service Brakes, ABS Actuator & Master Cylinder Reports
- Spongy or hard brake pedal travel
- ABS / Brake warning light illuminated
- Extended stopping distance / pedal vibration
“My headlight is absorbing moisture & causing my light to have a shortage.”
“Vehicle will flash warnings on dash the the blind spot assist in inoperative and the front passenger air bag malfunction. The active brake assist is also malfunctioning as the two white cars colliding is on. The dealership as tried to fix this issue 5 times and has tried argue...”
Electric Power Steering Assist & Suspension Noise Reports
- Sudden loss of electric power steering assist
- Steering wheel pull or highway wander
- Clunking / knocking noise over bumps
“Vehicle left/front headlight has water condensation and entire headlight doesn't work. Its pretty much not drivable. I brought the vehicle to a manufacturer dealership and they claim that the failure of the headlight is due to physical impact to the exterior of head light. The...”
“Entered parked vehicle and noticed very strong gas fumes. Vehicle would not start. Looked under the vehicle and noticed very large quantity of gasoline on the ground. Vehicle was towed to Mercedes dealership in Rochester, Michigan. Diagnosis was an incorrectly installed fuel l...”
Airbag Occupant Detection & Inflator Defect Reports
- SRS Airbag warning lamp illuminated
- Passenger occupant classification sensor failure
- Seat belt retractor lockup
“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 fa...”
“Vehicle will flash warnings on dash the the blind spot assist in inoperative and the front passenger air bag malfunction. The active brake assist is also malfunctioning as the two white cars colliding is on. The dealership as tried to fix this issue 5 times and has tried argue...”
Pre-Purchase Inspection Checklist for 2021 Mercedes-Benz GLC
Before purchasing a used 2021 Mercedes-Benz GLC, perform the following targeted inspections based on reported federal defect patterns:
Scan the OBD-II port under the dash for pending freeze-frame codes (e.g. P0300 misfires, P0087 fuel rail pressure, P0420 catalytic efficiency).
Test vehicle at low-speed stop-and-go and highway merges. Check for delayed reverse engagement or gear shift shudder between 2nd and 3rd gears.
Verify that all 0 NHTSA safety recall campaigns have been performed by an authorized dealership using the VIN.
Ensure the instrument cluster, center screen, and auxiliary charging ports operate with stable 12.0V–14.4V alternator voltage.
Defect & Reliability Q&A: 2021 Mercedes-Benz GLC
Is the 2021 Mercedes-Benz GLC a reliable used car?
The 2021 Mercedes-Benz GLC earns a 8.1/10 MazicBay Reliability Index based on 61 federal owner reports. Vehicles maintained under factory service schedules exhibit strong longevity past 150,000 miles.
What is the most frequent defect reported on the 2021 Mercedes-Benz GLC?
The leading complaint category is Engine Stalling, Oil Consumption & Cooling Defect Reports, with a median failure point around 40,500 miles (IQR: 34,897 – 59,250 mi).
Are there free recall repairs available for the 2021 Mercedes-Benz GLC?
Yes, the NHTSA records 0 safety recall campaign(s) for this model year. All safety recalls are performed 100% free of charge by authorized franchise dealerships regardless of vehicle warranty status.