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2018 Mercedes-benz C-class

The Verdict

68 Solid Pick

The 2018 Mercedes-benz C-class has 129 owner complaints filed with NHTSA. The most reported issues are body (62 complaints) and engine (43 complaints). With a Klunk Score of 68/100, it earns a "Solid Pick" rating. If you're shopping for a Mercedes-benz C-class, consider the 2021 model year which has 88% fewer complaints.

Safe Bet

The 2021 has 88% fewer complaints

View the 2021 Mercedes-benz C-class dashboard →

68

Klunk Score: Solid Pick

Fewer complaints than most vehicles. Generally dependable, but check the top problems below.

How is this calculated?

The Klunk Score ranks this vehicle year against all others in our database based on total owner complaints filed with NHTSA. 100 = fewest complaints (top tier), 0 = most complained-about. Scores above 60 are better than average; below 40 means more problems than most.

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Under the Hood

Each number is a complaint. Darker = bigger problem.

YearBodyBrakesElectricalEngineTransmission
200266671398
200326124487
200426415302
2005261703310
2006282428823
20072835814544
2008145156144614
200915124439409
201010683034016
201112012307629
201213323321946
2013163172968210
20146411170336
201517985119113
201611582715411
20171035311096
201862318433
201932510244
20202516113
2021201111
2022826100
2023136321
202453331

By Category

Body
62
Engine
43
Electrical
18
Brakes
3
Transmission
3

By Severity

1
55
2
69
4
5

Worst Problems

Compare Against

See how the 2018 Mercedes-benz C-class stacks up against rivals.

Complaints

Body 2

Sunroof causing dangerous pinch conditions. Roof tracks break and cause pinch areas with partial opening of roof

14d ago
Body 2

The contact owns a 2018 Mercedes-Benz C-300. The contact stated that while driving 70 MPH South on the interstate towards Miami, the front panel detached without warning. The contact pulled over to inspect the vehicle and became aware that the panel between the windshield and sunroof had detached. The contact stated that water started entering the vehicle from several areas. The sunroof was inoperable. The contact called the insurance company. The contact associated the failure with NHTSA Campaign Number: 23V854000 (Structure). The local dealer was contacted. The vehicle was not diagnosed or repaired. The manufacturer was contacted, but no additional assistance was provided. The approximate failure mileage was 83,000.

16d ago
Body 1

I have begun noticing symptoms of the adhesive failing, such as excessive wind noise coming from the front roof area and visible gaps/separation between the panel and the vehicle body. This poses a severe safety risk, as the panel could completely detach while driving and become a high-speed road hazard. No warning lights have appeared. The vehicle and component are available for inspection upon request.

1mo ago
Body 2

2018 Mercedes C300 - a hole rusted through the rear subframe causing structural safety concerns. This car has been routinely washed weekly and the frame should not have rusted through within only 8 years. This also led to a large repair bill.

1mo ago
Body 2

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

2mo ago
Body 2

****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.

3mo ago
Body 2

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)

3mo ago
Body 2

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

4mo ago
Body 1

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.

6mo ago
Engine 1

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.

8mo ago
Transmission 2

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.

9mo ago
Engine 1

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.

10mo ago
Body 2

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.

11mo ago
Body 1

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.

11mo ago
Body 2

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.

12mo ago
Body 2

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.

14mo ago
Body 2

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.

15mo ago
Body 2

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.

15mo ago
Body 2

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.

18mo ago
Engine 2

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.

19mo ago

129 total

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