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)

6 of 125 complaints match · Transmission & drivetrain · clear filters

Nov 19, 2025Transmission & drivetrain

I have a 2018 Mercedes Benz c63 amg which I purchased new in 2018. I have only 61,230 miles yesterday 11/10/2025 it started making a loud noise coming from the right rear. I drove to the Mercedes dealership in Belmont,Ca the technician mechanic told me that the rear differential was bad and need to be replace. Cost $7,000. I don't understand only 61,230 miles why did it go out so soon I always had the maintenance done. My warranty has expired. I did some research and found that there was a recall for 2018 Mercedes Benz c63 amg related to the rear differential. The recall was issued due to potential issues with the rear differential that could lead to a loss power to the rear wheels, increasing the risk of a crash. Owners were advised to contact their local dealerships for repairs or replacements as necessary.

NHTSA ODI 11700378

Jan 24, 2023Transmission & drivetrain

Error Code P052E Positive Crankcase Ventilation Regulation Valve Performance

NHTSA ODI 11503405

Jul 30, 2022Transmission & drivetrainEngine

Engine light ON with DTC code P052E

NHTSA ODI 11476706

Jan 4, 2022Transmission & drivetrainEngineFuel system

CYLINDER 1 SPARK PLUGS IS DAMAGED DUE TO PISTON DAMAGE, HOLE IN PISTON. IF EXTRA DAMAGE IS FOUND ON TEAR DOWN, COMPLETE ENGINE REPLACEMENT. This is direct from the repair facilities reports. While driving my 2018 C-300 there was smoking out of tail pipe, a rough vibration, hard to control the vehicle and it was starting to lose power. Not a good situation, had to pull over and have vehicle towed to the dealership. Worst part is this is a vehicle used to transport my 5 children to and from school and activities. My 16 year old also drives this vehicle, had he been driving this with this happening to him, the outcome could have been catastrophic. Vehicle has been inspected by 2 facilities; first was a certified Mercedes Benz repair facility and the second was the service dept. of the Mercedes Benz dealership I have serviced at for over 10 years. Mercedes refuses to cover repair costs or even acknowledge the major vehicle malfunction and safety issue this presents. , which is in my view ridiculous as cracked piston is not something that normally happens as the result of normal wear and tear, especially in a 3 year old luxury car. I have read several blogs on this same issue, Mercedesworld.org with over 400K members, reddit.com, benzworld.org, metrisforum.org, and numerous others. Please review these there are numerous people dealing with this and Mercedes is refusing to acknowledge. In addition, our Mercedes Benz service rep said these pistons were changed out in the 2019 model and newer due to these issues, he said he continues to see this issue with these models and advised Mercedes is well aware.

NHTSA ODI 11446178

Apr 15, 2019Transmission & drivetrainWheelsEngine

PURCHASED CAR JULY 2018. A/C LEAK IN AUG 2018 AND MARCH 2019; DEALER LOCATE LEAK. FRONT TIRE BLOWOUT WITHIN 6 MONTHS OF PURCHASE (DEC 2018) TRAVELING ON FREEWAY EVENING TIME APPROX 65 MPH; UNKNOWN REASON . SAME SIDE FRONT TIRE BLOW OUT 4 MONTHS LATER (MARCH 2019) DRIVING LATE EVENING ON A MAIN BOULEVARD TRAVELING 25 MPH AND RIGHT FRONT TIRE SHREDDED; HIT MINOR POTHOLE BOTH FRONT TIRES HAD TO BE REPLACED AND THE CAR ALIGNMENT CORRECTED. 1 MONTH LATER (APRIL 2019) RIGHT REAR TIRE LOOSING PSI EVERY 45 MILES; DEALER COULD NOT DETECT LEAK, POSSIBLE VALVE STEM. SAME VISIT DEALER REPLACED TWO REAR LEAKING SHOCK ABSORBERS AND NOTED RIGHT REAR TIRE HAD UNEVEN WEAR /RECOMMEND REPLACEMENT; TIRES HAVE 21,000 MILES. I WILL HAVE TO RETURN THE CAR TO THE DEALER FOR REPAIR. THE TRANSMISSION HAS A VERY HARD SHIFT WHEN I ACCELERATE MORE THAN MODERATE; THE HARD SHIFT CAUSES THE VEHICLE TO PAUSE AND JAR /JERK ABRUPTLY THAT ALMOST SEEMS LIKE YOU HIT SOMETHING. I HAD REPORTED THE ISSUE WITHIN 7 DAYS OF PURCHASE AND I WAS TOLD AMGS HAVE HARD SHIFTS. WHEN I INSISTED THERE WAS AN ISSUE A SECOND TIME IN MARCH 2019; THE ISSUE WAS ADDRESSED AND I WAS TOLD IT WAS THE COMPUTER SOFTWARE THAT REQUIRED AN UPDATE; THE UPDATE TEMPORARILY CORRECTED THE PROBLEM FOR APPROX 1 MONTH. THE VEHICLE HAS BEEN OUT OF SERVICE FOR APPROXIMATELY 13 DAYS SINCE PURCHASED 9 MONTHS AGO IN JULY 2018.

NHTSA ODI 11196192

Oct 16, 2018Transmission & drivetrain

NEW VEHICLE WITH UNDER 1000 TOTAL MILEAGE. INTERNAL PRESSURE CONTROL VALVE IN TRANSMISSION FAILED CAUSING MAJOR DAMAGE TO TRANSMISSION WITH METAL SHAVING FOUND IN TRANSMISSION PAN. TRANSMISSION AND FAULTY VALVE NEEDED TO BE REPLACED UNDER WARRANTY.

NHTSA ODI 11140526

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 →