Owners have filed 124 complaints
about the 2018 Mercedes Benz GLC 300 with NHTSA between 2018 and 2026.
The largest single group is the engine & cooling.
Across this model's run it ranks 1 of 8 worst.
The letter says how bad. This says what kind — whether this year drew
an unusual number of complaints, unusually dangerous
ones, or failures that arrived unusually early.
The dashed ring is 50 — the national norm. Further out is worse.
Complaint volume — 81
Against the median year of the Mercedes Benz GLC 300. 50 means typical for this
model; 100 means roughly double.
Severity — 62
12.1% of these complaints
involved a crash, fire, injury or death, against a national rate of
9.7%.
Early failure — 100
79% of failures with a mileage on record happened under
36,000 miles, against a national rate of
29%.
How 2018 compares with every other Mercedes Benz GLC 300
Odometer readings owners gave when they filed. About half of all
complaints include one.
Under 1,000 miles
511.9%
1,000 – 9,999 miles
1638.1%
10,000 – 24,999 miles
1126.2%
25,000 – 49,999 miles
24.8%
50,000 – 74,999 miles
716.7%
75,000 – 99,999 miles
12.4%
When owners complained
A spike years after the car went on sale usually means a part wearing
out on schedule across the whole fleet — the kind of pattern no single
owner can see from inside their own car.
Feb 2018peak 12Jul 2026
NHTSA investigations into the 2018 Mercedes Benz GLC 300
An investigation is the step before a recall: the agency has seen enough
complaints to look into a pattern itself. An open one means it thinks
something may be wrong and nothing has been fixed yet.
From 2000 through 2017, Takata produced millions of air bag inflators using two types of phase-stabilized ammonium nitrate ("PSAN") propellant -- propellant 2004 and propellant 2004L. After prolonged exposure to high temperature cycles and humidity, inflators using propellant 2004 can degrade, causing the propellant to burn too quickly when ignited. The rapid burning can cause the inflator to rupture during deployment, potentially causing serious or even fatal injury to vehicle occupants. See 2016 Blomquist Report at www.nhtsa.gov/sites/nhtsa.gov/files/documents/expert_report-hrblomquist.pdf.C...
Complaints that involved harm
Reports where the owner recorded a crash, a fire, an injury or a death.
Reserve, LA1 injured
AIR BAGS
I was backing out of my driveway and was putting the car in Drive when the airbag located in my steering wheel deployed without a reason. The car has not been inspected by anyone as of today. I was told there was a warning but that it was not of immediate attention in November of 2024.
NHTSA complaint #11648715 — an unverified report by a vehicle owner.
Mont Belvieu, TXCrash
UNKNOWN OR OTHER
I hydroplaned when driving in rainy weather and slid across freeway. Apparently break assist activated and automatically applied break. The car spun around and hit concrete barrier and then slid again across the freeway. At that point, a message was on display reading Collision Prevention Assist Plus Inoperative See Owners Manual. My vehicle had power but wouldn’t respond to the gas pedal and would not accelerate. I was unable to move vehicle out way of oncoming traffic. Luckily no one hit me and police arrived to divert traffic away from me. I turned vehicle off and on again but still was not able to move vehicle. I couldn’t even shift gear to neutral. Don’t appear to be much damage to front of car but the way the tires were turned indicate a suspension issue. I am waiting on quote.
NHTSA complaint #11434831 — an unverified report by a vehicle owner.
at 21,000 milesCarlsbad, CACrash1 injured
ELECTRICAL SYSTEM
WHEN I WAS PULLING INTO A PARKING SPOT AT A LOW SPEED, THE CAR ACCELERATED AND LURCHED FORWARD, HITTING A WALL, WHICH DEPLOYED THE AIRBAGS. WHEN THE CAR STARTED TO ACCELERATE, I HIT THE BRAKES BUT THEY DID NOT ENGAGE.
NHTSA complaint #11349114 — an unverified report by a vehicle owner.
at 21,000 milesCarlsbad, CACrash1 injured
SERVICE BRAKES
WHEN I WAS PULLING INTO A PARKING SPOT AT A LOW SPEED, THE CAR ACCELERATED AND LURCHED FORWARD, HITTING A WALL, WHICH DEPLOYED THE AIRBAGS. WHEN THE CAR STARTED TO ACCELERATE, I HIT THE BRAKES BUT THEY DID NOT ENGAGE.
NHTSA complaint #11349114 — an unverified report by a vehicle owner.
at 21,000 milesCarlsbad, CACrash1 injured
ELECTRONIC STABILITY CONTROL (ESC)
WHEN I WAS PULLING INTO A PARKING SPOT AT A LOW SPEED, THE CAR ACCELERATED AND LURCHED FORWARD, HITTING A WALL, WHICH DEPLOYED THE AIRBAGS. WHEN THE CAR STARTED TO ACCELERATE, I HIT THE BRAKES BUT THEY DID NOT ENGAGE.
NHTSA complaint #11349114 — an unverified report by a vehicle owner.
at 20,000 milesGarnet Valley, PACrash
UNKNOWN OR OTHER
AUGUST 8, 2019 WHILE PARKING MY CAR IN A GAS STATION AND GOING AT A LOW RATE OF SPEED I EXPERIENCED A SUDDEN ACCELERATION OF MY VEHICLE. I WAS UNABLE TO STOP THE CAR AND AS A RESULT HIT THE SIDE OF A BUILDING. THE CAR WAS TOWED AND REPAIRED. MERCEDES CORPORATE WAS NOTIFIED AND THEY SENT A MECHANIC TO CHECK THE CAR. ON AUGUST 21, 2019 I WAS INFORMED THAT MERCEDES FOUND NO EVIDENCE OF A MALFUNCTION. I WAS ALSO INFORMED THAT I COULD NOT HAVE THE CAR EVALUATED BY A THIRD PARTY. AROUND OCTOBER OF 2019 I HAD MY VEHICLE RETURNED TO ME FROM THE COLLISION CENTER. ON OCTOBER 24, 2019, AGAIN WHILE I WAS PARKING ON MY STREET AT A LOW SPEED THE VEHICLE ACCELERATED, THIS TIME I WAS ABLE TO PUT IT IN NEUTRAL, APPLY THE BRAKES AND AVOID AN ACCIDENT. AGAIN, I CALLED MERCEDES AND THE CAR WAS THEN TAKEN TO THE DEALERSHIP. ONCE AT THE DEALERSHIP I WAS TOLD THAT THEY COULD NOT LOOK AT THE CAR UNTIL MERCEDES CORPORATE GAVE THEM THE OK. I WAITED THREE WEEKS AND WAS THEN TOLD THE CAR HAD NO PROBLEMS. WHEN I PICKED UP THE CAR I DID ASK IF THE DEALERSHIP CHECKED THE CAR AND I WAS TOLD NO. MERCEDES SENT SOMEONE TO LOOK AT THE VEHICLE. WHEN I GOT HOME I OPENED THE HOOD AND FOUND IT FULL OF DRIED LEAVES. I GARAGE MY CAR BUT IT LOOKED LIKE THE CAR SAT ON THE LOT FOR THREE WEEKS IN THE WEATHER. I AM STILL DRIVING THIS VEHICLE AND WAITING FOR IT TO HAPPEN AGAIN. I WOULD HATE TO SELL IT AND HAVE SOMEONE HAVE A SEROUS ACCIDENT. I ALSO TRIED TO HAVE A LOCAL MECHANIC CHECK THE VEHICLE BUT THEY DID NOT WANT TO GET INVOLVED WITH THE ISSUE.
NHTSA complaint #11301580 — an unverified report by a vehicle owner.
The most recent complaints
In the owners' own words, exactly as filed with NHTSA.
Manalapan, NJ
ENGINE
Error code P052E71 on a 2018 Mercedes-Benz GLC 300 4MATIC means the Positive Crankcase Ventilation (PCV) Regulator Valve Performance has a malfunction, specifically that the partial-load ventilation valve actuator is blocked. By research, i found that this is a very common problem on those engines, and no recalls from the company to fix their fault.
NHTSA complaint #11753763 — an unverified report by a vehicle owner.
San Diego, CA
POWER TRAIN
Component Failure: The vehicle is equipped with the M274 2.0L turbocharged engine, which suffered a major internal mechanical defect. An authorized Mercedes-Benz dealership diagnosed the vehicle at 79,504 miles with a malfunction in the crankcase ventilation system alongside severe internal defects, quoting a total repair estimate of $9,851 to perform extensive engine work. Safety Risk: This known manufacturing defect involves premature failure and cracking of the pistons, which poses an immediate safety hazard due to potential catastrophic engine failure and sudden, complete loss of motor power while driving at highway speeds. The manufacturer has failed to offer an extended warranty or recall for this known issue on the 2018 model year.
NHTSA complaint #11741952 — an unverified report by a vehicle owner.
San Diego, CA
ENGINE
Component Failure: The vehicle is equipped with the M274 2.0L turbocharged engine, which suffered a major internal mechanical defect. An authorized Mercedes-Benz dealership diagnosed the vehicle at 79,504 miles with a malfunction in the crankcase ventilation system alongside severe internal defects, quoting a total repair estimate of $9,851 to perform extensive engine work. Safety Risk: This known manufacturing defect involves premature failure and cracking of the pistons, which poses an immediate safety hazard due to potential catastrophic engine failure and sudden, complete loss of motor power while driving at highway speeds. The manufacturer has failed to offer an extended warranty or recall for this known issue on the 2018 model year.
NHTSA complaint #11741952 — an unverified report by a vehicle owner.
Carmel, IN
UNKNOWN OR OTHER
Safety Issue: Infotainment display screen produces scrambled pixels during Apple CarPlay navigation while driving. Description: When Apple CarPlay is connected and navigation is in use, the vehicle's infotainment display screen suddenly produces scrambled pixels, rendering the map and display unreadable. This malfunction occurs without warning while the vehicle is in motion, creating a dangerous visual distraction for the driver and uncertainty of where and when to turn or exit. This is a known, recurring issue. On January 7, 2021, I brought this problem to Mercedes-Benz of Indianapolis (Repair Order #624027), where a firmware update was applied and the issue was allegedly resolved. The fix has not proven permanent — the problem has since recurred and continues to present a safety hazard while driving. Despite this being a widely documented issue affecting numerous Mercedes owners, Mercedes-Benz has not issued a recall or technical service bulletin that I am aware of. My dealer is requiring a diagnostic fee of over $250 to inspect the vehicle, and Mercedes-Benz USA customer service has been unreachable. Requested Action: I am requesting that NHTSA investigate this issue and consider whether a Technical Service Bulletin or recall is warranted given the safety implications of a sudden display malfunction while driving.
NHTSA complaint #11732752 — an unverified report by a vehicle owner.
Carmel, IN
ELECTRICAL SYSTEM
Safety Issue: Infotainment display screen produces scrambled pixels during Apple CarPlay navigation while driving. Description: When Apple CarPlay is connected and navigation is in use, the vehicle's infotainment display screen suddenly produces scrambled pixels, rendering the map and display unreadable. This malfunction occurs without warning while the vehicle is in motion, creating a dangerous visual distraction for the driver and uncertainty of where and when to turn or exit. This is a known, recurring issue. On January 7, 2021, I brought this problem to Mercedes-Benz of Indianapolis (Repair Order #624027), where a firmware update was applied and the issue was allegedly resolved. The fix has not proven permanent — the problem has since recurred and continues to present a safety hazard while driving. Despite this being a widely documented issue affecting numerous Mercedes owners, Mercedes-Benz has not issued a recall or technical service bulletin that I am aware of. My dealer is requiring a diagnostic fee of over $250 to inspect the vehicle, and Mercedes-Benz USA customer service has been unreachable. Requested Action: I am requesting that NHTSA investigate this issue and consider whether a Technical Service Bulletin or recall is warranted given the safety implications of a sudden display malfunction while driving.
NHTSA complaint #11732752 — an unverified report by a vehicle owner.
Palm Coast, FL
STRUCTURE:BODY
While driving on interstate 4 in Florida with our grandchildren going approximately 70 mph the sunroof on our 2018 Mercedes GLC just exploded no object came into the vehicle and while glass came into the vehiclenot all the glass that made up the sunroof came into vehicle suggesting a pressure issue as apparently blew out
NHTSA complaint #11723228 — an unverified report by a vehicle owner.
Kingwood, TX
POWER TRAIN:AUTOMATIC TRANSMISSION
The contact's friend owns a 2018 Mercedes-Benz GLC 300. The contact stated that while the owner was driving at an undisclosed speed, the accelerator pedal was depressed, but the vehicle failed to accelerate as intended, and the gear shifter independently shifted to neutral(N). No warning lights were illuminated. In addition, the contact stated that the failure was persistent. The contact stated that the owner forced the gear shifter out of neutral(N). The vehicle was taken to the dealer, where it was diagnosed that the transmission control unit had failed and needed to be replaced. The vehicle was not repaired. The contact related the failure to an unknown recall, but the VIN was not included in a recall. The manufacturer was made aware of the failure, and a case was filed. The contact was advised to contact the NHTSA Hotline to report the failure. The failure mileage was unknown.
NHTSA complaint #11708077 — an unverified report by a vehicle owner.
at 90,000 milesRosedale, NY
POWER TRAIN
The contact owns a 2018 Mercedes-Benz GLC300. The contact stated that while driving at various speeds, the vehicle shifted into gear initially without warning. The contact stated that while stopped at a light, the vehicle shut off with the "Transmission Malfunction Stop" message displayed on the instrument panel. The contact was unable to move the vehicle, and the vehicle was towed to an independent mechanic. The mechanic ran a diagnostic test on the vehicle and initially stated that the front drive wheel sensor was defective; however, the contact was then informed that there were no issues with the sensor. Neither the dealer nor the manufacturer was notified of the failure. The vehicle was not repaired. The failure mileage was approximately 90,000.
NHTSA complaint #11702561 — an unverified report by a vehicle owner.
Westford, MA
UNKNOWN OR OTHER
I have P052E71 error code. It’s a crankcase ventilation malfunction. Seems to be a common issue reported widely online on various forums. Mercedes should place a recall on this. The car has 55k miles on it.
NHTSA complaint #11699931 — an unverified report by a vehicle owner.
at 60,000 milesChesapeake, VA
AIR BAGS
The contact owns a 2018 Mercedes-Benz GLC300. The contact stated that while operating the vehicle, the message "Front Air Bag Malfunction" was displayed, and the horn became inoperable. The vehicle was taken to the local dealer who diagnosed that the steering column and air bag clock spring were faulty and needed to be replaced. The vehicle was not yet repaired. The manufacturer was notified of the failure and informed the contact that the VIN was not included in NHTSA Campaign Number: 17V627000 (AIR BAGS). The contact stated that the vehicle had experienced the failure listed in the recall. The failure mileage was 60,000.
NHTSA complaint #11698503 — an unverified report by a vehicle owner.
Hoover, AL
ELECTRICAL SYSTEM
I had the engine light come on and took it to the dealership. They quoted me over 8 thousand dollars to fix. I took it to a repair shop that works on luxury cars and they fixed it for less than 1000 dollars. I had to have the transducer fixed in the turbo in my engine and when they did that they found oil in the electrical harness. That was caused by the oil seperator. They told me that it was a manufacture defect that has been well documented and to take it back to Mercedees Benz. They looked and found the oil but said my car did not produce a code and could not fix it. We escalated it to corporate that reviewed my case and said they still would not fix until it produced a code. Mercedees implemented an extended warranty for my car back in 2022 for emissions. They said they would cover it if it produces a code. I researched this problem and it said it posses a risk to me, my passengers and the public if it quits running or causes a fire. Corporate said its not a problem yet.
NHTSA complaint #11698021 — an unverified report by a vehicle owner.
Hoover, AL
ENGINE
I had the engine light come on and took it to the dealership. They quoted me over 8 thousand dollars to fix. I took it to a repair shop that works on luxury cars and they fixed it for less than 1000 dollars. I had to have the transducer fixed in the turbo in my engine and when they did that they found oil in the electrical harness. That was caused by the oil seperator. They told me that it was a manufacture defect that has been well documented and to take it back to Mercedees Benz. They looked and found the oil but said my car did not produce a code and could not fix it. We escalated it to corporate that reviewed my case and said they still would not fix until it produced a code. Mercedees implemented an extended warranty for my car back in 2022 for emissions. They said they would cover it if it produces a code. I researched this problem and it said it posses a risk to me, my passengers and the public if it quits running or causes a fire. Corporate said its not a problem yet.
NHTSA complaint #11698021 — an unverified report by a vehicle owner.
East Northport, NY
VEHICLE SPEED CONTROL
While pulling into a parking spot with my foot hovering above/on the break, the car lurched forward as if someone had floored the gas pedal. As my foot was already on the break, I slammed down onto the break and the car came to a stop, several feet ahead of the top of the parking spot, and into the woods. I called roadside assistance for the vehicle to be towed to the dealership for repair, as I did not find it safe to drive it. The dealership was unable to replicate the issue, but they told me that due to the severity of the issue, they weren't supposed to check it themselves. Instead, I needed to report a case to Mercedes Corporate and the communication from here would be handled directly between corporate and myself. It's been over three weeks since this occurred, and I have not received communication that the car has been tested further, or any next steps. The car is at the dealership. It's also important to note that this same issue also happened months before, while backing out of a parking spot in reverse. I didn't report it because it was a confusing thing to happen and I couldn't believe a car would gas on it's own. When it happened a second time, I knew it was a problem. This was not a case of user error or the floor mat being in a wrong position. What component or system failed or malfunctioned, and is it available for inspection upon request? Speed control / yes How was your safety or the safety of others put at risk? The car spontaneously accelerated and could have caused harm if people or structures were in its path. Has the problem been reproduced or confirmed by a dealer or independent service center? Has not been reproduced Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? Not that I know of Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? No
NHTSA complaint #11687525 — an unverified report by a vehicle owner.
San Diego, CA
VEHICLE SPEED CONTROL
The car does not go into drive from reverse and will sometime automatically shift itself from a low drive gear (D1) into Neutral without warning. After this happens - the car also can't get back into D1. It takes about 20 seconds for the car to shift back into a Drive gear and it will jolt into D3 violently. This has been a scary experience on many occassions - especially at red lights when this happens and we can't get the car out of neutral for some time. This was diagnosed by mercedes dealership near us as a fawlty sensor in the transmission. It is extremely expensive to fix and is specific to mercedes meaning it has to be done by a MB dealership. We applied for good will for assistance but were denied. The car has been maintained very well - this is not a maintenance issue but a specific sensor failure of a mercedes sensor in the transmission. We are thankful no one was hurt - we had our 8 year old daughter in the car when stalling out several times at red lights and it's been a very scary situation.
NHTSA complaint #11676731 — an unverified report by a vehicle owner.
San Diego, CA
ENGINE
The car does not go into drive from reverse and will sometime automatically shift itself from a low drive gear (D1) into Neutral without warning. After this happens - the car also can't get back into D1. It takes about 20 seconds for the car to shift back into a Drive gear and it will jolt into D3 violently. This has been a scary experience on many occassions - especially at red lights when this happens and we can't get the car out of neutral for some time. This was diagnosed by mercedes dealership near us as a fawlty sensor in the transmission. It is extremely expensive to fix and is specific to mercedes meaning it has to be done by a MB dealership. We applied for good will for assistance but were denied. The car has been maintained very well - this is not a maintenance issue but a specific sensor failure of a mercedes sensor in the transmission. We are thankful no one was hurt - we had our 8 year old daughter in the car when stalling out several times at red lights and it's been a very scary situation.
NHTSA complaint #11676731 — an unverified report by a vehicle owner.
Reserve, LA1 injured
AIR BAGS
I was backing out of my driveway and was putting the car in Drive when the airbag located in my steering wheel deployed without a reason. The car has not been inspected by anyone as of today. I was told there was a warning but that it was not of immediate attention in November of 2024.
NHTSA complaint #11648715 — an unverified report by a vehicle owner.
at 62,700 milesPlymouth, MA
STEERING
The contact owns a 2018 Mercedes Benz GLC 300. The contact stated while attempting to park, a loud clanking noise was coming from the steering wheel as the air bag warning light illuminated. The vehicle was taken to the dealer where it was diagnosed that the clock spring in the steering wheel which caused the steering wheel to fail and the steering module needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and referred the contact to the NHSTA Hotline for assistance. The approximate failure mileage was 62,700
NHTSA complaint #11635080 — an unverified report by a vehicle owner.
Newton, MA
POWER TRAIN
Vehicle experienced transmission shifting issue after having driven for a period of 15 - 20 minutes, with engine oil temp reaching above 103/105 degrees C, transmission won't shift into Drive. Automatically pops into Neutral. Other times engine will stall, required complete restart. This creates hazard for operator and cars following behind as driver needed to steer vehicle out of the way of traffic while in Neutral. Independent MB repair shop and dealership scanned vehicle and identified with code P073E code. Dealer upgraded TCM control module software, and wanted to replace valve body in hope of remedy the problem. They were not 100% certain problem will be fixed. Independent repair shop indicated MB need to issue a recall for this problem, as they have seen many owner faced with the same problem. This is a big safety issue with problem of the transmission control module. Problem can be reproduced.
NHTSA complaint #11632530 — an unverified report by a vehicle owner.
Dacula, GA
ENGINE
I have engine light on and when I scanned it, I got a error code P052E For crankcase vent valve issues. It is most common problem with Mercedes-Benz Glc .
NHTSA complaint #11630856 — an unverified report by a vehicle owner.
Honolulu, HI
POWER TRAIN
Transmissiongoes into neutral while driving car at times. sometimes it will not go back into gear No movement of car on freeway potential of being hit from behind. problem reproduced, inspected by independent shop not inspected no lights
NHTSA complaint #11621613 — an unverified report by a vehicle owner.
Dayton, OH
FUEL/PROPULSION SYSTEM
Check engine light with code P052E.
NHTSA complaint #11604980 — an unverified report by a vehicle owner.
Rosedale, NY
SUSPENSION
when the car is in drive it will stop like it is in park unable to drive or put in reverse. This happens at random times on the road. The car will then skip gears and go into Neutral then skip an again on its own and go into drive.
NHTSA complaint #11592323 — an unverified report by a vehicle owner.
Rosedale, NY
ENGINE
when the car is in drive it will stop like it is in park unable to drive or put in reverse. This happens at random times on the road. The car will then skip gears and go into Neutral then skip an again on its own and go into drive.
NHTSA complaint #11592323 — an unverified report by a vehicle owner.
Rosedale, NY
FORWARD COLLISION AVOIDANCE: WARNINGS
when the car is in drive it will stop like it is in park unable to drive or put in reverse. This happens at random times on the road. The car will then skip gears and go into Neutral then skip an again on its own and go into drive.
NHTSA complaint #11592323 — an unverified report by a vehicle owner.
at 48,000 milesSouth Jordan, UT
SEAT BELTS
The contact owns a 2018 Mercedes-Benz GLC300. The contact stated that when the driver's side seat belt was buckled, the seat belt alarm chimed as if the seat belt was not buckled. The contact had to buckle and unbuckle the seat belt several times before the warning chime stopped. The contact had taken the vehicle to a local dealer who diagnosed the vehicle and determined that there was no issue with the seat belt system. The vehicle was not repaired. The contact stated that the failure was intermittent. The contact researched online and related the failure to NHTSA Campaign Number: 19V788000 (Seat Belts) however, the model year was not included. The manufacturer was informed of the failure. The failure mileage was approximately 48,000.
NHTSA complaint #11590569 — an unverified report by a vehicle owner.