Home · 2018 Mercedes-benz C-class · Complaints

What 125 owners told NHTSA about the 2018 Mercedes-benz C-class

These are the actual owner complaints behind this car’s reliability verdict, filed with the federal government, unedited. They’re unverified reports, not confirmed defects: read them as leads for your pre-purchase inspection, not a diagnosis.

All (125)Crash / fire / injury (5)Engine (39)Body & structure (15)Steering (13)Electrical system (12)Fuel system (10)Transmission & drivetrain (6)Airbags (5)Communication (5)Tires (5)Wheels (5)

39 of 125 complaints match · Engine · clear filters · page 1 of 2

Jan 9, 2026Engine

Check engine light comes on, Error Code P052E, after a lot of research, this is a known defective part by Benz. Huge safety issue not addressed by them. Very costly to fix for a customer. There is a new and improved replacement part from Benz indicating they are aware of the faulty old parts that are currently in those cars but yet they have failed to do a recall.

NHTSA ODI 11709871

Oct 23, 2025Engine

My vehicle only had 31,000 miles and I experienced engine failure. I bought a new engine for 16, 500. 00 dollars. Mercedes Benz did nothing. I almost got in to several accidents because the engine completely stop on the interstate. Almost got hit by several cars. This is unacceptable.

NHTSA ODI 11695170

Feb 3, 2025EngineFuel system

The engine light is on with only 35000 miles. Upon using an OBD2 scanner, error code P052e positive crankcase ventilation(PCV) malfunction was detected. It's a problem that I researched and noticed a lot of people having the same issue. I was told that this can cause the car to stall or shut down? This causes serious risk and safety issues to drivers, passengers, and pedestrians. With so many complains about this problem, I believe the manufacturer and dealers should take responsibility before tragedies happen.

NHTSA ODI 11640265

Aug 2, 2024Engine

I need the Crankcase ventilation valve replaced and have heard many complaints about this repair.

NHTSA ODI 11606218

Jul 27, 2024Engine

The day after I purchased my c300, the engine light popped on. I went back to dealer and they said it was a recall because of a crank case (PCV). I was upset because they never said anything about it. This was April of 2024. Note:(This Dealer was not Ray Catina’s of Edison). I went to Ray Catina’s in Edison for them to inspect car and I have been calling because I was told it was a national recall and it was on back order and should be here in June. It is now almost August and I called on the 23rd of July and received a call from Ray Catena on the 24th for them to tell me that “they were told that the new plan from Mercedes is to bring my car in and they will clear code. That’s what they are told to do.” To me, this is NOT fixing the issue. I am a little aggravated because I bought my car on [XXX] and have NOT been able to feel good because not sure what ramifications will come with me driving my car with this issue. I was told that driving with this engine light on and code that it will not harm my car. They now say Mercedes was told to reset the code and that will resolve issue? I believe this is a band aid not a fix!!! I’m a little upset. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11604857

Jun 23, 2024Engine

P052E positive crankcase ventilation regularly valve

NHTSA ODI 11595996

May 27, 2024Engine

Car needs an engine rebuild at 90K miles due to a cracked piston #1, a problem with a car that received regular oil change intervals and proper service should not have

NHTSA ODI 11590907

Apr 23, 2024Engine

Very common problem on all Mercedes - code P052E - second time on this car. Engine light, 2nd time on this car. Car is 2018 and has 45k miles. First time it was at 28037 miles. This is a MAJOR issue costing consumers $1500-$2500 to repair and needs a recall from manufacturer

NHTSA ODI 11584844

Mar 25, 2024Engine

CODE'S P052W-71 & P060A-00 THESE'S CODES HAS BEEN AN ISSUE WITH MERCEDES BENZ FOR QUITE SOME TIME NOW... ITS BEEN COMPLAINTS AFTER COMPLAINTS AND MERCEDES BENZ HAS NOT TAKING OWNERSHIP OF THE ISSUE.. THIS IS DEFINATELY A RECALL PLEASE LOOK INTO THIS I CAN BE REACH AT [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11579237

Mar 23, 2024Engine

The Valve for crankcase ventilation has a malfunction. The actuator is blocked.

NHTSA ODI 11579025

Mar 16, 2024Engine

Error code P052E Positive crankcase ventilation regulator valve performance

NHTSA ODI 11577820

Feb 20, 2024Engine

I have 33,000 miles on the vehicle and the check engine light came on. The code P052e came up Positive Crankcase Ventilation Regulator Valve Performance. I’m reading that many people have the same issue but there is no recall. Is there anything that can be done?

NHTSA ODI 11573044

Feb 5, 2024Engine

Check engine light code is positive crankcase ventilation regulator valve

NHTSA ODI 11569984

Jan 27, 2024Engine

An Engine Code P052E (positive crankcase ventilation regulatory valve) appeared and the vehicle only has 50K on it

NHTSA ODI 11568243

Oct 20, 2023Engine

My car was diagnosed with positive crankcase ventilation regulator valve performance failure. This should be recalled by the manufacturer because many c300 are having this very same issue.

NHTSA ODI 11551029

Oct 17, 2023Engine

Check engine light appeared.I took it to Mercedes and they said the crankshaft was faulty. I had to repair it and it cost me about $1800.00.

NHTSA ODI 11550481

Oct 5, 2023Engine

Engine code: P052e - the widest spread engine issue on Mercedes which fails emissions testing. Crankcase ventilator issue which leads to stalling.

NHTSA ODI 11548498

Sep 26, 2023Engine

Positive crank case valve failure. Check engine light on. Mechanic started this was extremely common and a costly repair on lower mileage Mercedes Benz vehicles. Mercedes Benz forums also mention this is extremely common and frustrating. This happened at slightly over 50k miles on my vehicle. Error code P052e

NHTSA ODI 11546676

Sep 15, 2023Engine

Engine light came on, checked with diagnostic machine shows a crank shaft issue. I have maintained the car with regular checks and maintenance. This has to be a defective part.

NHTSA ODI 11544819

Aug 5, 2023Engine

The check engine light has been coming on to indicate replacement of vent valve assembly According to the Mercedes Benz dealership. This is a commonly known problem in MB that they should replace and repair instead of charging customers $2k. My car has below 40k miles on it.

NHTSA ODI 11536699

Jul 26, 2023EngineFuel system

Check engine light came on. Had a diagnostic check and was told that the crankcase ventilation sensor needs to be replaced which will cost $1200.

NHTSA ODI 11534679

Jul 23, 2023EngineFuel system

My c300 2018 only has 50k and suddenly the engine light is on, when I check it shows that I need the Positive Crankcase ventilation valve replaced. it cost $2300. As I know a lot of people who own Mercedes have the same problem. Three mechanics claim it on almost all C, CLA, and GLA models. Please make Mercedes recall it finally.

NHTSA ODI 11533877

Jun 7, 2023Engine

Has 27000 miles out of warranty at 5 years. PCV code bad actuator. Looks like a common problem. Should be recalled.

NHTSA ODI 11525844

Apr 30, 2023EngineFuel system

The code I received is p052e from the check engine light. This can cause the car to stall out mid way through driving and cause a potential fatal accident. This is a common issue across C300 And GLC benz.

NHTSA ODI 11519686

Feb 22, 2023Engine

Engine light P052E, This seems to be a common problem with the C300.My concern is that Mercedes Benz hasn’t address the common issue. I own the car less than a year got it from Mercedes dealership and to be honest I expect Mercedes Benz to be better than the this to it customers

NHTSA ODI 11508602

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Working with the data? Download all 125 complaints as CSV · fetched from NHTSA July 14, 2026

How to use these: a complaint is one owner’s report, filed voluntarily and published unverified. Patterns matter more than any single story. If several owners describe the same failure at similar mileage, put that system at the top of your pre-purchase inspection list. Back to the full 2018 Mercedes-benz C-class verdict →