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)

Newest first · 125 complaints · page 1 of 5

Jun 16, 2026

Transmission failed, yes available for inspection Very bad safety issue Yes it has been confirmed by dealship Yes by the deanship Yes there was warning lamps that appeared in January 2026

NHTSA ODI 11744612

Jun 10, 2026Body & structure

****Please force Merces to recall all VIN's!******* NHTSA ID Number: 23V854000 1) Front glass roof panel came off while driving the car on the freeway. I didn't see or hear anything. When I got out of the car, I saw the entire piece has come off. This has caused my sunroof to malfunction, and it won't close now. I garage my car and barely drive it. I bought it used in Dec. 2021. There was about 46,000 on it in Dec 2021 and now (June 2026) the mileage is 51,000. Yes, the car is available for inspection. 2) I was on the freeway, didn't see it come off. No cars immediately in front or behind me. 3) There have been many complaints that this has happened, but Mercedes won't fix it and just say our VIN's are not part of the recall. Mercedes has not taken responsibility that this has affected more cars than they are admitting to. Mercedes says my VIN is not on their list too. 2018 Mercedes C 300 4Matic Sedan- 4) I will take to a Mercedes Dealership to get an estimate soon. 5) No warning lights or sounds.

NHTSA ODI 11743333

May 22, 2026Body & structure

Mercedes-benz usa. llc (mbusa) is recalling certain 2014-2020 c-class, cla, gla, s-class. glc, and gle vehicles. please refer to mbusa's recall report for specific vehicle details. the front roof panel located between the windshield and the panoramic sunroof may not have been bonded correctly to the vehicle during a prior repair, allowing the front panel to detach from the vehicle., Consequence A detached roof panel can become a roao hazard, increasing the risk of a crash I went to the dealership about this complaint 2 years ago not even knowing about an official recall of this exact problem. I don't drive my car as much because it was an issue that never got fixed. I was never told about a recall. They said there is a whistling and it could fly off (the panel)

NHTSA ODI 11739465

Apr 24, 2026

When I decelerate my brake lights don’t flash to warn the driver behind me that I am potentially slowing down .

NHTSA ODI 11733648

Mar 5, 2026Body & structure

The contact's wife owns a 2018 Mercedes-Benz C300. The contact stated that while washing the vehicle, a part of the panoramic roof started moving while depressing the glass. The contact stated that there was water leaking into the vehicle from the glass. Upon investigation, the contact discovered NHTSA Campaign Number: 23V854000 (Structure); however, the VIN was not included in the recall. The vehicle was not repaired. The manufacturer was notified of the failure, and a case was filed. The manufacturer confirmed that the VIN was not included in the recall. The contact was then referred to the NHTSA Hotline to report the failure. The failure mileage was unknown.

NHTSA ODI 11722229

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

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

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

Oct 8, 2025

Rearview Camera is not displayed when the vehicle is placed in reverse. The display shows a black screen. A Recall Notice has been published for other vehicles of the same year, make, and model. The failure of the Rearview Camera results in safety risks during normal use of the vehicle.

NHTSA ODI 11692113

Sep 26, 2025Seat belts

I have noticed the driver seat belt not retracting after usage. Upon looking online I saw a post about a recall. Called local Benz dealership and BenzUSA customer service both said my Vin is not part of the specified recall.

NHTSA ODI 11689895

Aug 19, 2025Body & structure

The contact owns a 2018 Mercedes-Benz C300. The contact stated that while driving approximately 60 MPH, a part of the panoramic roof towards the driver's side detached from the vehicle. The contact pulled over to inspect the vehicle. The part was no longer attached, and the contact had to continue driving. The failure caused additional electrical failures due to water entering the cabin of the vehicle. The contact stated that the sunroof failed to open, and the infotainment center was inoperable. The contact found information on NHTSA Campaign Number: 23V854000 (Structure); however, the VIN was not included. The vehicle was taken to the dealer, who related the failure to the recall; however, the vehicle could not be repaired under the recall because the VIN was not available. The vehicle was not repaired. The manufacturer was informed of the failure and opened a case. The manufacturer confirmed that the VIN was not included in the recall. The manufacturer referred the contact to the NHTSA Hotline to file a complaint. The failure mileage was approximately 109,000.

NHTSA ODI 11681537

Jul 7, 2025

I was driving around my neighborhood one day with my panoramic sunroof open and at the red light i wanted to close the sunroof (california summer sun is no joke) and it made this really big 'THUMP' noise, thought the sunroof glass cracked. After the big THUMP noise, the sunroof wouldnt close and this is after the light turned green so i am driving slowly because there was rattling noise coming from the sunroof and didnt want the sunroof to fly out from the car. So i had to pull over and try to figure out if its okay to drive with stuck sunroof with it rattling noise. after that i tried to close and open the sunroof and wouldnt move or do anything, it was just stuck. So i turned my hazzards on then drove slowly back home. after about 30 mins playing with sunroof in my garage, hoping that i will close (then at least i can still drive my car without being scared that it will fly out from my car), finally go it to closed but now it doesnt work at all. then i have found out that from 2014 to 2018 pano sunroof is known issue and there were safety recall on some pano sunroof already on this model. i called 6 places and they told me (besides from how many they had already repaired) the holder on the sunroof rail is broken so the whole rail assy needs to be replaced. imagine if i was on a freeway going 65+ and if this would have happend and this HUGE pano sunroof flew out from my car... this is very big safety issue and that probably why 2017 (same pano sunroof) was on a recall.

NHTSA ODI 11671664

Jun 4, 2025Body & structure

The contact owns a 2018 Mercedes-Benz C300. The contact stated that after washing the vehicle, the contact became aware that the adhesive attaching the rear window to the convertible top had started to detach. Upon further inspection, the contact became aware that water had seeped into the vehicle through the crack. There was no warning light illuminated. The local dealer was contacted; however, the vehicle was not diagnosed. The contact was also informed that the VIN was not under recall. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 49,000.

NHTSA ODI 11664906

May 28, 2025Tires

In August 2024, a Mercedes-Benz dealership in Salisbury, MD installed the wrong type of rear tires on my vehicle. I was not informed they were mismatched or inappropriate for my vehicle. I later drove across the country with my infant child in the backseat, believing the tires were new and safe. On April 17, 2025, a certified tire shop in Texas (Discount Tire) inspected the tires and told me they were not suitable for my car and were already too old to be considered new — despite having been installed just 8 months earlier. They refused to buy them back or reinstall them due to the age and mismatch. Additionally, the dealership had earlier failed to correctly diagnose my ABS system, citing water damage but doing no further inspection. They also missed a major coolant leak and water pump failure, despite charging me for multiple diagnostics. Their negligence in both diagnosis and tire installation directly put me and my child at serious safety risk, especially while traveling long distance at highway speeds.

NHTSA ODI 11663518

Mar 10, 2025Backup camera & sensors

I recently purchased a 2018 Mercedes C300 and I noticed the rear view camera will not show an image. It mechanically will open and all other cameras are fully functional but the image will not show instead I see a icon of a camera in a red crossed circle. When doing VIN serch on my vehicle I don't see any open recalls. However, I noticed that NHTSA campaign number 22V232000 has recalled this exact issue. Although the report 573 says for it applying to 2019 models but with a production date between 2017 to 2021 vehicles applying. So I believe this recall should also apply to my vehicle.

NHTSA ODI 11647340

Feb 12, 2025Fuel system

The contact owns a 2018 Mercedes-Benz C300. The contact stated that while the vehicle was parked inside the garage, there was a strong fuel odor inside the garage. The contact stated that there was fuel leaking from the vehicle. There were no warning lights illuminated. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not contacted. The failure mileage was approximately 52,300.

NHTSA ODI 11642176

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

Jan 23, 2025Seat belts

The contact owns a 2018 Mercedes-Benz C300 4Matic. The contact stated that the front passenger's and driver's side seat belts had failed to retract and return to the stowed position. The contact related the failure to NHTSA Campaign Number: 21V032000 (Seat Belts); however, the VIN was not included. The dealer was notified of the failure and informed the contact that there would be a cost for a diagnostic test. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure, but no assistance was provided. The failure mileage was approximately 59,000.

NHTSA ODI 11637991

Sep 30, 2024Visibility & wipers

The contact owns a 2018 Mercedes-Benz C300. The contact stated that while driving at an undisclosed speed, the rear window glass which was not properly bonded had become loosened. The vehicle was not diagnosed or repaired. The VIN was not included in NHTSA Campaign Number: 18V608000 (VISIBILITY). The manufacturer was not notified of the failure. The failure mileage was 50,000.

NHTSA ODI 11617349

Sep 12, 2024Body & structure

Problem a recall was done on certain Mercedes vehicles where the front panel of the roof between the panoramic sunroof and windshield has defects in gluing or bonding agent from the manufacture. I believe my vehicle is showing possible premature bonding agent issues below the surface of panel. Where the manufacture bonding glue is causing interior flaking and cracking and lifting from the stress of the wrong/incorrect specified bonding material not used during the manufacturing process . I am afraid that while driving my vehicle at highway speed has the opportunity / potential for my panel to eventually break off and cause damage of flying panel pieces to harm myself or other vehicles traveling on the road. I believe the wrong bonding material is also causing other issues with the panel and the workmanship material used. My vehicle falls under the year, make, W222 and I am already seeing issues with my panel that by being proactive on my vehicle then reactive. I don’t want to wait for my panel to fly off when early detection and rectification is the safest way/option. My second concern is that there has already been changing dates on this recall information sent out in 2017, 2019 and now 2021. I am worried!!

NHTSA ODI 11614170

Sep 9, 2024Steering

car has less than 34,000 miles on it. One day went to drive and the vehicle wouldn't turn and an error message popped up "power steering malfunction, check owners manual" Had it towed to dealer and they said they couldn't find anything wrong with it. According to the dealer, no sign of wear and tear, no physical damage,

NHTSA ODI 11613561

Aug 22, 2024Steering

The contact owns a 2018 Mercedes-Benz C300. While driving at various speeds, the contact could hear an abnormal sound from the transmission. The vehicle was taken to a local independent mechanic where it was diagnosed that the rack and pinion needed to be replaced. The vehicle was not repaired. The vehicle was then taken to a local dealer for diagnosis, but the failure could not be replicated. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 57,000.

NHTSA ODI 11610269

Aug 6, 2024Latches & locks

The contact owns a 2018 Mercedes-Benz AMG C63. The contact stated while attempting to refuel the vehicle, the fuel tank door would not open unless the excessive force was used. The failure occurred on several occasions. The vehicle was taken to a local dealer where it was diagnosed that the fuel tank door failure was a known manufacturing failure. The fuel tank door was replaced by the dealer on several occasions but the failure recurred. The vehicle was temporarily repaired with wiring to prevent the fuel tank door from closing. The manufacturer was made aware of the failure. The failure mileage was approximately 20,000.

NHTSA ODI 11606763

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

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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 →