Total Complaints
79 filings
MERCEDES-BENZ GLC 300 · model year
79 NHTSA complaints, 1 crash report, and 7 active recalls for this specific cohort.
NHTSA overall rating
Not crash-tested
New Car Assessment Program
The 2021MERCEDES-BENZGLC 300 carries 79 consumer safety complaints in NHTSA's Office of Defects Investigation database for this specific model-year cohort. Within that volume, owners reported 1 crash, 1 fire, 0 injuries, and 0 fatalities. No NCAP 5-star crash-test rating is available for this model year in the federal database.
Component-level analysis is where model-year complaints become actionable: the top complaint category for the 2021 GLC 300 is engine with 27 filings, followed by fuel/propulsion system (9) and exterior lighting (9). Concentration in one or two component groups is the classic signature of a systemic defect; a flat distribution usually reflects normal aging, warranty complaints, or isolated build-plant variability. This model year has 7 active recall campaigns, which means the manufacturer is obligated to remedy the covered defect at no charge for the life of the vehicle — the full NHTSA campaign numbers are listed below.
NHTSA currently has 15 investigation files overlapping the 2021 GLC 300. Owners comparing this cohort against neighboring years should pair the counters above with the complaint-by-year trend on the parent model page — a spike in a single year often tracks to a platform refresh, a new transmission supplier, or an updated ECU calibration. Use the related-complaint feed below to read raw owner narratives before deciding whether any pattern here affects your specific use case.
Total Complaints
79 filings
Crashes Reported
1 reports
Source
NHTSA ODI
Federal complaints database
At or below the fleet median complaint volume.
| Component | Count |
|---|---|
| ENGINE | 27 |
| FUEL/PROPULSION SYSTEM | 9 |
| EXTERIOR LIGHTING | 9 |
| ELECTRICAL SYSTEM | 7 |
| UNKNOWN OR OTHER | 6 |
| STRUCTURE:BODY | 3 |
| VISIBILITY/WIPER | 3 |
| VEHICLE SPEED CONTROL | 2 |
| FORWARD COLLISION AVOIDANCE: ADAPTIVE CRUISE CONTROL | 2 |
| FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING | 2 |
| FUEL SYSTEM, GASOLINE | 2 |
| POWER TRAIN | 2 |
| BACK OVER PREVENTION | 1 |
| AIR BAGS | 1 |
| LANE DEPARTURE: BLIND SPOT DETECTION | 1 |
FUEL SYSTEM, GASOLINE:DELIVERY:FUEL PUMP
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2021-2023 C-Class, E-Class, S-Class, CLS, SL, GT, GLC, GLE, GLS, and G-Class vehicles. Please refer to MBUSA's recall report for specific vehicle details. The fuel pump may shutdown, which can result in a loss of drive power.
ELECTRICAL SYSTEM:SOFTWARE
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2017-2022 CLA-Class, GLA-Class, GLE-Class, GLS-Class, SLC-Class, A-Class, AMG GT-Class, C-Class, E-Class, S-Class, SL-Class, GLC-Class, CLS-Class, GLB-Class, and G-Class vehicles. Please refer to MBUSA's recall report for specific vehicle model de
BACK OVER PREVENTION: SENSING SYSTEM: CAMERA
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2019-2021 CLA-Class, GLE/GLS-Class, A-Class, E-Class, E-Class Coupe and Convertible, GLA/GLB-Class, GLC-Class, CLS-Class, and AMG GT-Class 4-door Coupe vehicles. Please refer to MBUSA's recall report for specific vehicle model details. The MBUX m
AIR BAGS:SENSOR:SIDE IMPACT
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2021 CLS450, AMG E53, AMG CLS53, E350, E450, AMG GT43, AMG GT53, 2020 S450, S560, G550, AMG GLC63, 2020-2021 GLC300, and AMG G63 vehicles. The side crash sensor connectors may come loose, which could delay the activation of air bags and seatbelts
COMMUNICATION
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2017-2019 C300, E300, 2018-2020 CLA250, 2020 CLS450, AMG E53, AMG GT53, GLE450, 2018 AMG E63, AMG GTA, 2017-2020 GLA250, GLC300, 2019 GLC350, AMG GLC43, 2017-2018 GLE350, 2019 AMG GLC 43, GLC350, GLE400, 2017 GLS450, S550, C300 Cabrio, and 2018-201
ELECTRICAL SYSTEM:SOFTWARE
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2016 - 2021 CLA-Class, GLA-Class, GLE-Class, GLS-Class, SLC-Class, A-Class, GT-Class, C-Class, E-Class, S-Class, CLS-Class, SL-Class, B-Class, GLB-Class, GLC-Class, and G-Class vehicles. Please refer to the Part 573 report for specific vehicle mod
EXTERIOR LIGHTING:HEADLIGHTS
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2019-2022 GLC 300, 2020 GLC 350e, and 2020-2022 AMG GLC 43 vehicles. The headlights may be incorrectly adjusted too high and create a glare for oncoming traffic. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicl
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 Engine Light came on and the engine does not run properly and causes engine damage. We had to drive it slowly, under 45 mph, to the nearest dealership. This is a safety issue. To replace the oil pump control valve solenoid and the wire harness for this feature is $5009.00 at Mercedes-Benz. The part cost is about $300 retail, and the rest is all labor fees.
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 Engine Light came on and the engine does not run properly and causes engine damage. We had to drive it slowly, under 45 mph, to the nearest dealership. This is a safety issue. To replace the oil pump control valve solenoid and the wire harness for this feature is $5009.00 at Mercedes-Benz. The part cost is about $300 retail, and the rest is all labor fees.
The contact owns a 2021 Mercedes-Benz GLC300. The contact stated that the passengerâs side headlight was developing fog, causing the light to be dim. The vehicle was taken to the dealer, who diagnosed the vehicle and determined that the headlight needed to be replaced. The vehicle was not repaired. The contact learned of NHTSA Campaign Number: 22V261000 (Exterior Lighting); however, the VIN was not included. The manufacturer was informed of the failure and confirmed that the VIN was not included in the recall. The manufacturer referred the contact to the NHTSA Hotline to report the failure. The failure mileage was 41,000.
Mileage: 41,000
Cylinder head valve seat leak ..vehicle Mia fires and check engine light on
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
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
While I was driving on the Garden State Parkway, my vehicle experienced a sudden loss of power and persistent misfires and my check engine light came on. I was put in a position of a significant crash risk due to the fact that the vehicle loss sudden acceleration power while entering the parkway. I was almost rear ended by another vehicle. I drove immediately to a Mercedes-Benz dealer. The dealer confirmed a catastrophic cylinder head engine failure. The vehicle had only 39,000 miles. After some investigating, there have been numerous complaints from vehicle owners with the same issue on the M264 engine (which is what my vehicle has). I request that the NHTSA investigate the premature cylinder head engine failure. Not only was I put at risk for a possible significant accident, the manufacturer has refused to consider some reimbursement for my $10,000 repair. The vehicle was only 3,000 miles out of warranty at the time of the engine failure. A safety issue seems to be warranted and pos
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.
The vehicle lost power and will not operate over 40 mph/2000 rpms
Twice my car slowed down tremendously in traffic because of a bad cylinder head. I drive a 2021 Mercedes GLC 300 4matic with 33,529 miles. In reviewing other complaints, this is a common and known complaint. My check engine light came on and I could not go over 40 mph. This is very dangerous.
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, wait five seconds and then turn it back on the car operates like nothing has happened. Here is when it has happened: 1.In a drive-thru lane to get some food 2.Waiting in a left-hand turn land 3.Driving through a parking lot at 10 mph 4.Driving on a road at 45 mph The date below is the last occurrence.
Check engine light came on. Code was P219D mixture formation is irregular on cylinder 2. Informed today, the cylinder will need to be replaced entirely for about $10,000. Concerned that although this did not happen to me, others have stated the vehicle completely stalls while driving.
what happened? While driving, all of sudden, engine light was on and shaky with rough vibration consequently loss of power. I pulled over and turned off engine. Engine light disappeared after restarted. It happened again and had diagnostics at the dealership. Software update was given at first solution. However, next day, engine light on again, visited the dealership and it turned out there are leak on cylinder head. It seems a known issue. there are similar cases where vehicle could have been in critical situation. [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
The headlights stopped working due to water entering the assembly unit. First one side went out and then eventually the other side went out. The car was brought in to the dealership to fix and they stated it wasnât covered. Iâm recently learning about a recall of this issue with my type of car and Iâm being told that my vehicle is not included in the recall.
Have been getting condensate inside vehicle headlights inwhich have cause the headlight to completely not work anymore.. There is no damage to headlight which means to be cause due to a problem with the seal. Checked with local and also statewide Mercedes advisors which was told there isnât a recall for my vehicle inwhich I looked online and found an recall for vehicles just like the one I have.. Recall number 22V261000-Recall Date 04-14-2022. Iâm asking for my vehicle to be inspected and repaired free of charge . Thanks and sorry for the bother - Canât drive vehicle at night due to headlight malfunction and itâs very unsafe for me and kids and family
Have been getting condensate inside vehicle headlights inwhich have cause the headlight to completely not work anymore.. There is no damage to headlight which means to be cause due to a problem with the seal. Checked with local and also statewide Mercedes advisors which was told there isnât a recall for my vehicle inwhich I looked online and found an recall for vehicles just like the one I have.. Recall number 22V261000-Recall Date 04-14-2022. Iâm asking for my vehicle to be inspected and repaired free of charge . Thanks and sorry for the bother - Canât drive vehicle at night due to headlight malfunction and itâs very unsafe for me and kids and family
Have been getting condensate inside vehicle headlights inwhich have cause the headlight to completely not work anymore.. There is no damage to headlight which means to be cause due to a problem with the seal. Checked with local and also statewide Mercedes advisors which was told there isnât a recall for my vehicle inwhich I looked online and found an recall for vehicles just like the one I have.. Recall number 22V261000-Recall Date 04-14-2022. Iâm asking for my vehicle to be inspected and repaired free of charge . Thanks and sorry for the bother - Canât drive vehicle at night due to headlight malfunction and itâs very unsafe for me and kids and family
Head problems
In September 2024 my vehicle's engine light came off and the car was struggling to accelerate, especially in highway. I took it to Mercedes Benz of Cincinnati and they acknowledged the fault, made some repairs (under warranty) but the mechanic told us he had already seen quite a few of these cars needing the engine to be replaced. The problem keep coming back and took in in May 2025 (4 months after warranty expired) with the same exact issue. Now they said it is a cylinder head that needs replacement and that it will cost me $10K. This problem has now been reported by several drivers for this model car within less than 5 years of being made. In Canada, the same type of engine has seen same problem so Mercedes extended the warranty for 15 years on the cylinder heads. They need to do the same for the GLC engines and cover our repairs.
Our 2021 Mercedes is 4 years old and had the engine light come on. The vehicle has always been maintenance by Mercedes and well taken care of. The engine had a Cylinder Head Failure which resulted in a $7600 repair for a 4 year old vehicle. Mercedes refused to offer a good will repair. This is A major issue reported in 2015â2016 M274 engine which can lead to catastrophic engine failure 1. These failures often result in loss of power, strange engine noises, and in severe cases, engine seizure. The damage can extend to the cylinder head, especially if broken piston fragments impact the combustion chamber. This is a major risk for all owners of 4 cylinder Mercedes. Mercedes of Canada has already issued an extended warranty but owners of US Mercedes vehicles are left on the hook for the bill and risking their lives while this is a known issue.
Data as of 2025. Sources: NHTSA Office of Defects Investigation (ODI) complaints database, NHTSA recall campaign API, NHTSA NCAP crash-test ratings, and NHTSA FARS for fatality cross-reference.
Read our methodology — how this data is sourced, computed, and verified.