2021 Mercedes-Benz GLC Class

These are unverified consumer reports filed with NHTSA, shown as submitted.

• 12/30/2025· ENGINE

  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 possibly a recall because of the many complaints on the GLC website. Please investigate.

• 12/29/2022· AIR BAGS,LANE DEPARTURE,FORWARD COLLISION AVOIDANCE

  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 the the active brake assist is functioning normal.

• 12/24/2024· ELECTRICAL SYSTEM

  Mercedes App displays low battery alert. Brought to dealer who stated Mercedes told them (dealer) to inform anyone coming in with this issue to just disregard the alert in the app. Had the battery checked anyway. At the conclusion was told I had to “drive the car longer so the battery would recharge”.

• 12/18/2024· UNKNOWN OR OTHERFire

  Driving short distance home when the bottom of Mercedes GLC 300 caught fire without warning or notification. I was unaware when a good Samaritan screamed out your car is on fire. Pulled over and she helped me out. Seconds later the car exploded into flames and the car was demolished.

• 12/12/2023· POWER TRAIN,ENGINE,FUEL/PROPULSION SYSTEM

  This is the 3rd incidence of this issue (July, Oct, Dec), but we have been advised that a software update is not yet available from the manufacturer. In all instances, we were travelling at a normal rate of in-city traffic (30-45 mph) and all of sudden the vehicle will not accelerate above 25 mph regardless of the position of the throttle. My dealer, Mercedes Benz of Tampa, advises that the problem can only be corrected permanently with a "software update" which is not yet available. This is a major safety issue, especially on the highway, as the vehicle could suddenly and unexpectedly be unable to accelerate, in fact, decelerates at random times without warning.

• 12/07/2023· FUEL SYSTEM, GASOLINE

  The contact owns a 2021 Mercedes-Benz GLC300. The contact received notification of NHTSA Campaign Number: 23V445000 (Fuel System, Gasoline) however, the part to do the recall repair was unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure. VIN tool confirms parts not available.

• 12/04/2024· FUEL/PROPULSION SYSTEM

  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 independent mechanic, who diagnosed a failure with the fuel pump. The vehicle was not repaired. The vehicle was then towed to the dealer, who confirmed the diagnosis. The vehicle was not repaired. After investigating the failure, the contact related the failure to NHTSA campaign 23V880000 (Fuel System, Gasoline), but the VIN was not included. The manufacturer was notified of the failure; a case was opened, and the contact was referred to the NHTSA hotline for assistance. The failure mileage was 80,000.

• 11/29/2021· ELECTRICAL SYSTEM,BACK OVER PREVENTION

  The contact owns a 2021 Mercedes-Benz GLC300. The contact received a recall notification for NHTSA Campaign number: 21V354000 (Back Over Prevention, Electrical System). The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was notified of the issue. The part was not available for the repair. The contact had not experienced a failure. Parts distribution disconnect.

• 11/24/2024· ELECTRICAL SYSTEM,EXTERIOR LIGHTING

  My vehicle suddenly starting getting moisture in the passenger side head light.Many people brought this my attention.After some time of moisture the head light begin to flicker on and off while I was driving.Then it just went out and stopped working.Eventually I took it to the dealer and they informed me that my vehicle didn't have a recall for this issue.As I search the Internet I found that lots of other customers experienced this same exact issue.I called Mercedes USA and they informed me to present the issue to you all. Thank You in advance for reviewing my concern.

• 11/19/2024· EXTERIOR LIGHTING

  My headlight is absorbing moisture & causing my light to have a shortage.

• 11/12/2025· ENGINE

  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.

• 11/03/2025· FUEL/PROPULSION SYSTEM

  The vehicle lost power and will not operate over 40 mph/2000 rpms

• 10/28/2025· ENGINE

  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.

• 10/27/2024· ENGINE

  While drive check engine light came on and car would go past 20 miles per hour. This is the second occurrence. First time this occurred October 2023 and covered under warranty. Head Gasket blew.

• 10/24/2025· ENGINE

  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.

• 10/17/2024· ENGINE

  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 NHTSA Hotline to file a complaint. The failure mileage was approximately 56,600

• 10/04/2024· ENGINE,FUEL/PROPULSION SYSTEM

  Vehicle has a known engine failure. Leaking valve in Cylinder head. Cylinder 3 injector is faulty

• 09/28/2021· ENGINE

  The contact owns a 2021 Mercedes-Benz GLC300. The contact stated that while his wife was driving at an undisclosed speed, the "Add 1 quart of oil" message was illuminated. The contact's wife did not pull over and continued driving while the "Stop driving" warning message was illuminated. The contact's wife was able to drive to the residence. The contact noticed there was a quart of oil on the floor from the engine compartment and detected a burning oil odor. The vehicle was towed to the dealer and the dealer replaced the O-ring. The vehicle was repaired but remained at the dealer. The manufacturer was not made aware of the failure. The failure mileage was unavailable.

• 09/27/2022· ELECTRICAL SYSTEM,FUEL/PROPULSION SYSTEM

  My car was bought new in October 2021 & I began having problems after having it for 6 months & the mileage at that time was about 4000 miles - it was in April 2022 & the check engine light came on & I had a loss of power to where it slowed down & would not go any faster than about 30/35 miles an hour going on a straight road way & no faster than about 10 miles an hour going uphill. The engine sounded funny as well. It had to be towed to the dealership for repair. This incident happened again a month later & it was towed to the dealership at that time. The next incident just happened this month (mileage=6620) & again it was towed to the dealership for repair. Same scenarios all 3 times. This last incident, I was told that it is glitch & they don't really know what is causing my car to basically go into "limp mode"; however, they are awaiting a software update that they expect will resolve the problem, but they are not sure when it will be available for installation & did not give me a timeline. In the meantime, I was given back my car as I was the 2 other times without a resolution or security that my car is doing to make it to & from my destination. The car is still under warranty & just under a year old now. I was told by the dealership that they have no other customers complaining of this problem & they feel it is very isolated. I asked them to reach out to their corporate office in hopes of making a deal with me as I have lost all confidence in the car, but they reported having no luck in reaching anyone to discuss my problem. The 3 incidents where the car had to be towed were very scary for me as other cars were blowing their horns at me because I could not accelerate & go any faster & when I was going up a hill - it was really bad. I was very lucky that all 3 times happened not far from my home & not on the interstate as the outcome could have been very bad for me in regards to my safety.

• 09/22/2025· ENGINE

  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.

• 09/18/2022· UNKNOWN OR OTHER

  The HVAC system has a very had odor that could impact our respiratory health, and giving us headaches when we drive. I wanted to share with you my current situation that I believe relates to the Mercedes HVAC Class Action Settlement (https://www.mercedeshvacsettlement.com/). My 2021 GLC300 Mercedes is experiencing exact same issues as described in the Mercedes HVAC Class Action Settlement even though the settlement only covers vehicle models up to 2019. I have been a loyal Mercedes customer for over 20 years and took in the vehicle 4 times to address the bad HVAC odor that occurs 3 to 4 times a day when I turn on the HVAC. It has a moldy, mildew-y, or similar odor emanating from the vehicle’s HVAC system. The dealership admitted they did smell the odor but there is nothing they can do to address it after they changed the air filters and cleaned the evaporator coil. I then escalated to MBUSA Escalation team to request a full refund or replacement based on the Arizona Lemon Law statute and they were of no assistance and completely denied my request stating that the vehicle is working as intended. I even went to a Lemon Law attorney and provided them all the 4 service documentation records showing that I took the vehicle in 4 times and evidence from dealership admitting that there is an odor from the HVAC for the same issue with no root cause or resolution to address the odor from the HVAC. The attorney passed on taking my case, which I believe is a good solid case. Do you have any further ideas on what I can do start a class action lawsuit against Mercedes or investigate extending Mercedes HVAC Class Action Case 1:17-cv-01701-AT to include vehicle models beyond year, 2019? Based on my observation this is still happening in Mercedes vehicle models 2020 and newer.

• 09/11/2023· ENGINE

  The contact owns a 2021 Mercedes Benz GLC300. The contact stated while driving approximately 65 MPH, the vehicle lost motive power and failed to accelerate properly while depressing the accelerator pedal. The contact pulled over to the side of the road and turned off the vehicle. After restarting the vehicle, the vehicle operated normally. The cause of the failure was not determined. The local dealer and manufacturer were contacted and informed the contact that the VIN was not included in NHTSA Campaign Number: 23V445000 (Fuel System, Gasoline). The contact stated that the vehicle had experienced the failure listed in the recall. The failure mileage was 28,000.

• 09/04/2026· ELECTRICAL SYSTEM,EXTERIOR LIGHTING

  My 2021 Mercedes-Benz GLC 300 is not currently included in NHTSA Recall 22V-261 / Mercedes-Benz Campaign 2022050005, but my vehicle is experiencing substantially the same defect described in that recall. Moisture/water entered the left headlamp assembly/electrical connection, resulting in condensation/water accumulation and damage/corrosion around the headlamp electrical module/connector. The headlamp system subsequently malfunctioned. Recall 22V-261 describes a condition where the headlamp electrical connection may not be watertight, allowing moisture ingress and potentially causing headlamp failure. My vehicle appears to exhibit the same condition even though my VIN is excluded from the recall population. I am requesting that NHTSA review whether the affected population for Recall 22V-261 may need to be expanded.

• 09/03/2021· VEHICLE SPEED CONTROL,ENGINE

  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.

• 08/30/2026· POWER TRAIN,ENGINE,FUEL/PROPULSION SYSTEM

  The vehicle is experiencing an intermittent, sudden, and life-threatening drop into "limp home mode" while driving, creating an severe speed differential with surrounding traffic.First Incident (50,584 miles): The vehicle entered limp mode. Authorized Mercedes service center scanned the car, confirming Fault Code P019185 (Rail pressure sensor malfunction / signal above permissible limit value). The dealer applied an Engine Control Module software patch under Mercedes TSB LI07.70-P-078047.Second Incident (53,695 miles): Less than 3,000 miles later, the exact same sudden powertrain failure recurred. The vehicle drastically lost propulsion power immediately after exiting a high-speed freeway, leaving the driver in an incredibly vulnerable, unsafe position.The manufacturer's documented software remedy has completely failed to fix the underlying powertrain defect, leaving a known hardware component failure unaddressed while actively endangering vehicle occupants.

• 08/28/2026· UNKNOWN OR OTHERFire

  While the vehicle was being operated normally, it caught fire. We were driving on a summer day in August. Conditions were humid, with temperatures in the mid-80s. The vehicle was on the return leg of an approximately 30-mile drive. Traffic was somewhat heavy, with speeds generally below 20 mph and occasional stops. We first noticed a slight burning smell, followed shortly afterward by a distinct puff of white smoke coming from under the hood on the passenger side, near the windshield. We immediately decided to stop the vehicle and get out. Within approximately 30 seconds, we observed the first visible flames. Within about one minute, the fire had spread rapidly and the vehicle was engulfed in flames. By approximately 3½ minutes, the entire front half of the vehicle had been destroyed by the fire. Parts of the vehicle were blown off during the fire, with some debris traveling across the roadway and into the nearby woods. Fortunately, there were no injuries because we recognized the danger and exited the vehicle quickly.

• 08/27/2025· ENGINE

  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)

• 08/21/2025· EXTERIOR LIGHTING

  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 wasn’t covered. I’m recently learning about a recall of this issue with my type of car and I’m being told that my vehicle is not included in the recall.

• 08/07/2024· ENGINECrash

  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 failure, the vehicle would resume normal operation upon restart of the engine. The vehicle was initially taken to a dealer but the dealer could not duplicate the failure. The failure worsened over time which resulted in the contact being rear-ended by another vehicle. The air bags did not deploy upon impact and the contact was not injured. A police report was filed and the contact was able to drive the vehicle away from the scene of the accident. The vehicle was taken to various dealers and independent mechanics where each diagnosed the vehicle with a defective cylinder head. The manufacturer was notified by the dealer about the failure and the manufacturer agree to cover half the cost of the repair. The vehicle had yet to be repaired. The failure mileage was approximately 35,000.

• 07/18/2025· ELECTRICAL SYSTEM,EXTERIOR LIGHTING,VISIBILITY/WIPER

  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 isn’t 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. I’m asking for my vehicle to be inspected and repaired free of charge . Thanks and sorry for the bother - Can’t drive vehicle at night due to headlight malfunction and it’s very unsafe for me and kids and family

• 07/09/2021· VISIBILITY/WIPER

  On day zero when I bought the car, it was raining. The new car wiper was shattering or making bumpy movements. It was not cleaning the heavy rain water or it was spotty. The Mercedes mechanic told it is a known issue and there is no permanent fix. They just changed the wiper blade and put solvent on windshield which may be good for few days/weeks and need to take the car everytime, I have this issue till I have warrantee. This is very annoying and safety issue in Houston rainy season. It can happen anytime in the middle of busy road and under rain.

• 07/09/2021· STRUCTURE,UNKNOWN OR OTHER

  Excessive frame rust, the pictures I included are all the patches that have been done to the frame so far.

• 06/19/2021· FUEL/PROPULSION SYSTEM

  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 line bracket. New bracket was installed and problem was corrected.

• 06/16/2025· ENGINE

  Head problems

• 06/16/2021· FUEL/PROPULSION SYSTEM

  Fuel line malfunctioned, car stopped , gasoline was pouring out from under the hood. I was "lucky" that it did not catch fire, fire department showed up, closed the street, car was towed, dealership " replaced high-pressure line of fuel system high pressure pump". It all started without a warning, suddenly after about 1 month of driving ( 1000 miles) a brand new Mercedes GLC300.

• 06/15/2022· VEHICLE SPEED CONTROL,FORWARD COLLISION AVOIDANCE

  Driving on I75 in Georgia using Distronic speed control. This system scans highway speed control signage and automatically adjusts the vehicle speed based on speed limit signs. Unfortunately the state of Georgia has deployed MINIMUM SPEED 40 signs alongside the highway that are identical in size and appearance to SPEED LIMIT signage. The next result is the car automatically dropping the current speed (say 70 mph) to 40mph with heart stopping effects, particularly in heavy traffic. Turning off the automatic speed control eliminates the problem. This is a major safety flaw that, left unfixed, will results in loss of life.

• 06/06/2024· VISIBILITY

  The contact owns a 2021 Mercedes-Benz GLC300. The contact stated that while his spouse was driving approximately 35 MPH, the passenger’s side side-view mirror fractured without impact. The dealer was contacted to schedule an appointment; however, the vehicle had not been taken to the dealer to be diagnosed or repaired. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was 25,000.

• 05/30/2022· STRUCTURE,VISIBILITY/WIPER

  Sunroof glass panel exploded outward. Fabric retractable interior sunroof liner did contain all of the fragmented safety glass. No prior impact on or to the sunroof. If the interior fabric sunroof liner had been retracted, the interior of the vehicle would have been showered with the glass shards impacting the driver and all passengers. There was no warning. A loud sound similar to gunshot occurred as the sunroof failed. The vehicle was driven to a local windshield repair facility for examination. I contacted and notified Mercedes Benz USA of the incident. They have not done a follow-up as of this date. I contacted Mercedes Benz of Anchorage AK and will do a follow-up with that dealership on May 31 2022.

• 05/20/2026· ENGINE

  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 fix! After intense negotiations, they agreed to fix it for $4,205.58, which was better, but still, that’s a lot to pay for a manufacturer’s defect! My car is a 2021 with only 67,540 miles on it.

• 05/18/2025· ENGINE

  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.

• 05/14/2025· ENGINE

  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 2015–2016 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.

• 05/05/2026· ENGINE

  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 an issue with the wiring in the solenoid. I'm not sure if there is a fire risk because of the frayed wires.

• 04/28/2025· ELECTRICAL SYSTEM,EXTERIOR LIGHTING

  I seen a recall for certain 2021 GLC 300 vehicles for moisture in right side headlamp, causing headlamp to blow (go out). This happened on my 2021 GLC 300. Same moisture issue, same year, same model, however, my vin number does not show that it has a recall. I believe this safety issue needs to be expanded to include my vehicle. Same issue, same year, same make and same model

• 04/26/2021· ENGINE,FUEL/PROPULSION SYSTEM

  ON APRIL 21, 2021 AT ABOUT 1800 (TIME), LESS THAN 45-HOURS AFTER PURCHASE OF THE NEW 2021 GLC 300 VEHICLE, THE INTERNAL COMBUSTION (ENGINE) MISFIRED AND ABRUPTLY MALFUNCTIONED WHILE IN STEADY ACCELERATION AT 65-MPH. MY FAMILY AND I WERE HEADED EASTBOUND ON THE CA-60 FREEWAY IN LANE THREE (LEFTMOST, FASTEST LANE). AS SOON AS THE ENGINE SPONTANEOUSLY SPUTTERED, IT ABRUPTLY STOPPED AND INTENSELY SHOOK THE ENTIRE CAR VIGOROUSLY, AGGRESSIVELY, AND CONTINUOUSLY WITH NO ABILITY FOR CONTROL NOR FOR THE OPTION TO CONTINUE TO ACCELERATE. THERE WERE THREE CARS BEHIND MY VEHICLE ALSO ACCELERATING AT THE SPEED OF TRAFFIC (65-MPH) THAT ALSO ABRUPTLY SCREECHED TO A HALT TO STEER CLEAR OF MY UNUSUALLY MALFUNCTIONING VEHICLE. THIS WAS THE MOST TRAUMATIC EVENT THAT HAS EVER HAPPENED TO MYSELF AND MY FAMILY IN OUR LIFETIME. AS YOU CAN IMAGINE, WE FEEL EXTREMELY FORTUNATE IN HAVING SURVIVED THIS HORRENDOUS, UNEXPECTED, AND CRUEL SAFETY RISK AS NO COLLISION WAS FORTUNATELY REPORTABLE. THE VEHICLE'S MALFUNCTIONING AND PERFORMANCE ISSUE HAD PLACED US IN AN EXTREMELY HIGH-RISK OF SAFETY CONCERNS AND NEAR MOMENTS FROM MY OR MY FAMILY'S HEALTH-RELATED TRAGEDY AS THE HALT OF NUMEROUS CARS WITHIN THE FREEWAY CLOSELY SWERVED-AWAY FROM OUR DIRECTION. AS YOU CAN IMAGINE, WE ARE SEVERELY, PHYSICALLY, EMOTIONALLY, AND MENTALLY DISTRAUGHT DUE TO THE MANUFACTURING DEFECT TO THE 2021 GLC 300 ENGINE. AFTER 30-HOURS OF CONTINUED QUESTIONING, ANALYSIS AND DISCOVERY, IT WAS CONFIRMED OF VALVE TRAIN COMPONENT DEFECT CAUSING MAJOR DOWNSTREAM EFFECTS TO THE ENGINE AND IMMEDIATE INABILITY TO ACCELERATE ON THE HIGHWAY WITH DIRECT SERIOUS LIFE THREATENING RISK TO A NEW VEHICLE AND MY FAMILY WITHIN IT. PLEASE CONSIDER THIS DETRIMENTAL INCIDENT FOR OTHER'S GLOBAL SAFETY THROUGH MY TRAGIC EXPERIENCE.

• 04/25/2025· EXTERIOR LIGHTING

  The contact owns a 2021 Mercedes-Benz GLC300. The contact stated that there was condensation inside the front passenger’s side headlight housing after it had rained. The contact then stated that while driving at night, the passenger’s side headlight failed to operate as needed. There was no warning light illuminated. The dealer was notified of the failure, and the contact was informed that the vehicle was not included in NHTSA Campaign Number: 22V261000 (Exterior Lighting); and the contact was provided an estimate for the repair. The vehicle was not repaired. The manufacturer was notified of the failure but offered no assistance. The failure mileage was approximately 92,700.

• 03/29/2021· ENGINE

  2021 MERCEDES GLC. CONSUMER WRITES IN REGARDS TO VALVE SPRING FAILURE AND STALLED ENGINE. *LD THE CONSUMER STATED SHORTLY AFTER PURCHASING THE VEHICLE, THE VALVE SPRING BROKE CAUSING THE ENGINE TO FAIL WHILE DRIVING. THE FAILURE MILEAGE WAS 199. THE CONSUMER STATED THE ROADSIDE ASSISTANCE GROSSLY UNDER ESTIMATED IT'S ARRIVAL TIME. ALSO, THE CONSUMER WAS IN AN UNFAMILIAR AREA BUT, ROADSIDE ASSISTANCE REQUIRED AN ADDRESS BEFORE SENDING THE TOW TRUCK. THE CONSUMER HAD TO WALK THE STREET TO FIND AN ADDRESS ON A HOME. THE CONSUMER FELT THE DEALERSHIP ATTEMPTED TO DOWNPLAY THE FAILURE AS A SIMPLE FIX. THE MANUFACTURER WAS NOTIFIED AND OFFERED GOODWILL ASSISTANCE WHICH THE CONSUMER ACCEPTED. *JS *JS

• 03/27/2022· FORWARD COLLISION AVOIDANCE

  Unexpected Severe braking when changing into turn lane. Unexpected severe braking when approaching intersection with no cars in intersection or on either side of car.

• 03/22/2025· ENGINE

  On [XXX] my GLC 300 AWD while driving back from work started shaking, went into limp mode, engine started misfiring and check engine light came on. Pulled over into a parking and called Mercedes-Benz road side assistance, they sent a tow truck and the car was towed to the Mercedes-Benz of Oklahoma City. The service department informed us of cylinder head failure and told SUV needs cylinder head replacement that would be covered under the extended Mercedes warranty. As of March 22, 2025 SUV is still at the Mercedes dealer and not fixed. This is the second time in past few months GLC went into limp mode and lost power and acceleration while on road, it was towed to the Mercedes dealer. They initially said they couldn't find anything wrong but later performed an update of engine management software on the recommendation of Mercedes-Benz USA. Car was fixed at that time. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

• 03/15/2026· POWER TRAIN

  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 particular but nothing for US.

• 03/14/2025· ENGINE

  While driving my vehicle on March 3, 2025 the check engine light came on. Additionally my vehicle began to shake. I was scheduled for a service appointment on March 5, 2025 and told the service department the check engine light need to be addressed. Upon inspection, it was determine the cylinder head needed to be replaced due to a leaking exhaust valve. Estimated cost of $8,818.12. I was devastated and disappointed we had a 2020 Mercedes GLC 300 had the EXACT SAME PROBLEM in 2023. The cost to repair was estimated at $9000!!! How coincidental is that 2 vehicles in the same family have the same problem on newer model vehicles!!!! After researching the web, we discovered that the warranty was extended on the M260 cylinder head however my engine is M264 engine just for RWD cars. Mercedes will not cover it even though this is the 2nd GLC 300 that WE have reported the problem with the cylinder head. They would not even replace the part and we pay for the labor. I am truly disappointed and most likely never be a Mercedes purchaser again. Especially since they cannot stand behind their product. The cylinder head failed and caused my daughter to be placed in harm's way by beginning shaking while driving. This could have caused an accident and put others at risk. This problem has been confirmed by 3 different dealerships on 2 different vehicles( 2020 and 2021 Mercedes GLC 300). It has been inspected by the dealership that confirms it is leaking and needs to be replaced and confirmd it was not the negligence of the driver. There were no warning signs besides the check engine light coming on.