Owner-reported complaints naming the engine system, filed with NHTSA
Data refreshed
Reports naming the engine itself — including stalling, misfires, oil consumption, cooling and internal engine components. Every record below is an owner-reported complaint about the 2018 Mercedes-Benz GLC 300 submitted to NHTSA — not a confirmed defect, not a recall and not a manufacturer bulletin. 28 reports on file name it.
Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.
The 25 most recent of 28, in the owner's own words
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.
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.
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.
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.
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 .
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.
Vehicle showing check engine light, connected a reader to the vehicle and it shows a code of P052E .. ( Positive Crankcase Ventilation Regulator)
I brought my vehicle in to get serviced because the check engine light came on and I was told it was CODE PRESENT P0521E71 VALVE FOR CRANK CASE VENT. HAS MALFUNCTION / BLOCKED. I was told I have warranty on it so Mercedes of Massapequa took the car to fix.I was told the part was fixed but oil was found on my engine computer from the crank case vent malfunctioning but the warranty won't cover it although it was a direct result of a part that was covered part and had caused the damage.They gave me my car back and my car is worse it has problems starting it requires multiple cranks and the air conditioner has a fuel smell when turned on and I am unable to pass my vehicle inspection because my check engine light it still on.I spoke to the corporate office and they said because I have too many miles they can't do a courtesy and honor the cost and referred me back to the dealer and the dealer told me they will bring the cost to fix the computer leak to $6000 although it was due to a faulty part on their behalf .I am beyond upset my car is non longer reliable or safe to drive.Mercedes of massapequa ignored all my calls after they gave me back my vehicle that was worse after they claimed they fixed it.
Car failed to accelerate due to faulty fuel pump, fuel tank, etc. Car stopped and died several times in the middle of heavy traffic. Mercedes Benz of West Houston, Sewell Dealership, has my car that was towed to them late afternoon on 3/5/2024. I have owned a Mercedes for over 40 years and never had this occur or be scared due to the car’s lack of performance.
Engine light error code P-052e71. The crankcase ventilation valve malfunction. This is reported by a lot of customers.. It cost about $2000 to fix this problem.
The contact owns a 2018 Mercedes-Benz GLC300. The contact stated that while driving 65 MPH, the vehicle started to hesitate while depressing the accelerator pedal. The contact stated that the vehicle also started shaking and vibrating with the check engine warning light illuminated. The contact managed to pull the vehicle off the highway and had the vehicle towed to a dealer. The vehicle remained in the dealer's possession for several weeks before the contact was informed that it was discovered that the piston rings were burned and that the cylinder head was warped. The manufacturer was notified of the failure but had not yet receive a response. The vehicle was not repaired and remained in the possession of the dealer. The failure mileage was approximately 9,200.
I m having issue with te code po52e its annoying i fixed and still the same issue
Complete engine failure after 55,000 miles determined that there was a broken piston #1 in the car. This required a complete engine replacement. This is a known problem by Mercedes with the engine model M274 there are numerous reports of the same problem in this engine over several models and years. The engine was 5000 miles out of warranty however this problem seems to occur in alot of vehicles from Mercedes with this engine. There is an active class action lawsuit in California regarding this. Mercedes seems to be ignoring this issue and or not dealing with it to date.
Code P052E PCV crankcase valve ventilation
Vehicle is switching gears automatically from Drive to Neutral in the middle of the road, in the middle of driving, VERY dangerous situation. I cannot put in reverse sometimes it switches back to N. . It always switch his back to neutral. Thankfully no accidents. Don’t know what to do?
Keep having check engine light due to fault code *P052E71 The valve for crankcase ventilation malfunction-the actuator is blocked Many of 2018 Mercedes Benz GLC 300 experienced the same issue.
Vehicle stopped while driving on road. Car show "active brake assist malfunction" on the dashboard, immediately following the car will not accelerate. Shut the car off and restart, then the "check engine light" comes up. The active brake assist does not come up again, but the check engine light states on. I have taken the vehicle 5 times for this issue to the dealer, car is currently at the dealer. Reason of my report, is that I consider this situation extremely dangerous and should be investigated further. [XXX] INFORMATION Redacted PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6).
Code P052E---crankcase Vent Solenoid Valve issue---------common issue with this model----under 65,000 miles
positive crank case oil separator valve part # 274-090-56-00-80 failed error code- P052E caused check engine light. Had repaired today through warranty. known issue for all Mercedes Benz. If paying out of pocket expect to spend 2,000.
P052E PCV value problem requiring a $2000 repair. Has happened 2 times in 70k miles.
I was driving when engine light came on.It then went into limp mode.The car would not accelerate we me trying to cross a busy 60mph road.I was almost killed.The code after it was tested p2138 .Pedal position sensor.This fault almost killed me....
Crankcase Breather Intake Line - Part number 274090560080 is malfunctioning and replacement of this requires over $2,000 at the dealership. This is a very common issue among the Mercedes-Benz vehicles that uses this same engine.
P052e crankcase vent malfunction
Check engine light came on with code P052E : Positive Crankcase Ventilation Regulator Valve Performance.
P052E postive crankcase ventilation regulator valve
Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.
Categories with enough reports to have a page of their own
Data on this page last refreshed .