Mercedes-Benz C300 water leak problems

Filed Mar 5, 2026 · Body · CA

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 the federal safety agency 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 federal safety agency Hotline to report the failure. The failure mileage was unknown.

Filed Aug 19, 2025 · Body · 109,000 miles · TX

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 the federal safety agency 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 federal safety agency Hotline to file a complaint. The failure mileage was approximately 109,000.

Filed Nov 7, 2024 · Visibility · 100,000 miles · FL

The contact owns a 2016 Mercedes-Benz C300. The contact stated that while driving during rainy weather conditions, water leaked through the sunroof into the interior of the vehicle. In addition, while attempting to close the sunroof, the sunroof glass remained open and slanted on the front and rear diver's sides. Upon further investigation, the contact related the failure to the federal safety agency Campaign Number: 16V087000 (Visibility); however, the VIN was not included. The vehicle was taken to a local dealer where it was determined that the sunroof rails had failed and needed to be replaced. The vehicle was not repaired due to the cost. The manufacturer was notified of the failure and referred the contact to the federal safety agency Hotline for assistance. The failure mileage was approximately 100,000.

Filed Jun 14, 2024 · Electrical, Visibility · 169,000 miles · MD

The contact owns a 2012 Mercedes-Benz C300. The contact stated that after opening the sunroof and then attempting to close the sunroof, the sunroof failed to fully close. The contact had to open and close the sunroof several times before the sunroof closed. Additionally, the contact stated that there was water entering the vehicle from the sunroof which caused electrical failures. The contact stated that the vehicle was drivable, but the "Anti-Theft" warning light illuminated. The contact stated that several other warning lights were later illuminated, and the vehicle would not start. The contact had the vehicle towed to a dealer who diagnosed the vehicle and determined that water had damaged the driver’s side electrical wiring harness. The vehicle was not repaired. The manufacturer was informed of the failure. The failure mileage was approximately 169,000.

Filed May 21, 2024 · Body, Driver assistance · CA · crash

While I was driving to work in a heavy rain my abs malfunction light came on in my car. I decided to take it to the Mercedes-Benz dealership in Fresno. They said it was the ABS module that needed to be replaced. After being in the shop for almost 3 weeks they said it was fixed. When I went to pick it up, the moment I turned it on the ABS malfunction light came on again. I was told that it was okay to drive and they would have somebody come check it out at my work the next day. My car went back into the shop for another week and they could not figure out what was wrong with it. They did take pictures and the second time I took it in they noticed a bunch of water underneath the floorboard. By this time, I had lost confidence in them fixing my car the manager basically kicked me off the lot and told me never to go back again. So I continued to drive my car since I was told it was okay first time they fixed it. Short while later, I rear-ended another car. The ABS system did not warn me that I was too close. When I took my car in to get the body work fixed I was also given a name of somebody who would be able to fix the electrical problems and insurance would pay for it. He was able to fix the ABS system but could not find where the short was that controlled the passenger seat and the driver side back seat window and for the needle that tells me if my car is overheating. Nobody could figure out where the water had been coming from. It wasn't until recently when we just had a heavy storm that I noticed water leaking from inside the car through a seam. The running boards on the top of my car were not installed correctly so water seeps in there during rains and then it travels down underneath my floorboards and sits which was the cause of the shorts in my electrical system. My concern is that I don't know how bad other components of the car might be that one of the wires might at any of the wires might short while I'm driving now but unable to download receipts which I have

Filed Apr 29, 2024 · Body · 6,000 miles · OR

The contact owns a 2022 Mercedes-Benz C300. The contact stated that while the vehicle was parked, the contact became aware that the seal had detached from the driver’s side front door. The contact stated that due to the failure, water entered the driver’s seat causing a short circuit in the electrical system. The vehicle was taken to a dealer and was determined to be a manufacturing defect. The vehicle was not repaired. The manufacturer was made aware of the failure and referred the contact to the federal safety agency Hotline. The vehicle was not repaired. The failure mileage was approximately 6,000.

Filed Aug 7, 2023 · Visibility · 125,000 miles · FL

The contact owns a 2013 Mercedes-Benz C300. The contact stated that while driving at an undisclosed speed during a rainstorm, and rainwater leaked from the sunroof and the front driver’s side window into the cabin of the vehicle. The cause of the failure was not yet determined. The manufacturer and local dealer were not notified of the failure. The failure mileage was 125,000.

Filed Jan 9, 2023 · Electrical · PA

Due to apparently deficient sunroof water drain system design, rainwater and condensation entered the passenger compartment under the carpeting, potentially damaging the vehicle's electrical wiring. The vehicle is available for inspection upon request. A dealer has inspected and confirmed the damage. Initial symptoms of the problem were wet carpeting and the sound of water sloshing around under the floor of the passenger compartment.

Filed Jan 29, 2022 · Brakes, Electrical · NY

I’ve had 2 c300 Mercedes models in the past 8 months both used and were driving fine until rain water and car washes caused electrical damage there is a water leaking issue that goes into the floorbeds of the vehicle that causes the car to malfunction

Filed Aug 27, 2020 · Electrical · 56,023 miles · LA

When driving on the bridge the piece of my sunroof flew off I pulled over it was raining and the inside of my car got wet the motor on my sunroof no longer works as the water leaked through. I picked up as much of the pieces as I could but the part was run over.