2018 Mercedes-Benz GLC 300: check engine light

Filed Nov 6, 2025 · Electrical, Engine · AL

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.

Filed Dec 16, 2024 · Engine · GA

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 .

Filed Jul 28, 2024 · Fuel system · OH

Check engine light with code P052E.

Filed Mar 29, 2024 · Engine · FL

Vehicle showing check engine light, connected a reader to the vehicle and it shows a code of P052E .. ( Positive Crankcase Ventilation Regulator)

Filed Mar 27, 2024 · NC

Mercedes Benz C300 P052E positive crankcase ventilation regulatory valve. Check engine light is on and the replacement is expensive. This is known issue, discussed in most MB forums. Please have it as manufacturers recall. By the time you come across this I may have already paid it some place to get it fixed... but want to help others. Thank you. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Mar 26, 2024 · Electrical, Engine · NY

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.

Filed Jan 21, 2024 · Engine · LA

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.

Filed Nov 20, 2023 · Engine · 9,200 miles · FL

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.

Filed Nov 1, 2023 · Fuel system · SC

Positive crankcase ventilation regulator valve performance code P052E failed at 58k miles. Checked engine light came on after diagnostic scanner equipment .

Filed Jul 22, 2023 · Engine · VA

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.

Filed Jun 16, 2023 · AR

At 35,000 miles the check engine light came on, error message was checked at a Mercedes dealership and read a Crankcase Vent Valve malfunction. The malfunction causes issues with acceleration and causes a high RPM idle and accelerates engine wear. After researching online, this problem has occurred to a huge number of 2015-2018 Mercedes GLC 300’s, with many people having to make this $2,000 repair every 2 years.

Filed Jun 3, 2023 · Driver assistance, Electrical · TX

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).