2011 Mercedes-Benz C-Class Fuel System Problems

On 8/3/2023 we could smell a strong gasoline smell inside and outside our 2011 Mercedes C300. We towed the car to a Mercedes specialty repair shop for inspection. The found that the passenger side fuel pump cover (which is a large cylinder assembly actually) was leaking due to cracked plastic. Gas vapors could be detected outside the car, in the trunk, and in the car as the gas tank is right under the back seat. Our mechanic said he had just fixed another Mercedes with the exact same problem. Apparently this is a well known defect and I understand that Mercedes has an extended warranty for later models. We believe the extended warranty should be extended to our 2011 C300 which has only 55,000 miles.

The contact owns a 2011 Mercedes-Benz C300. The contact stated after adding more than 3 gallons of fuel to the vehicle, there was a strong fuel odor inside the cabin of the vehicle. The contact stated that the failure had been recurring and was making him unwell. The vehicle was taken to the dealer, where it was diagnosed and determined that the failure was related to NHTSA Campaign Number: 12V557000 (Fuel System, Gasoline). The vehicle was not repaired. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was unknown.

Each time I filled my gas tank, there was an overpowering odor of gasoline inside the car and outside on the passenger side. Once the tank would get down below 3/4 of a tank, the odor would dissipate until down to a 1/4 of a tank it would go away completely.

My check engine light came on approximately one month ago. Once tested it indicated a fuel vapor leak. I pulled out of a driveway and a large stream of fuel spilled all over the roadway. Approximately 7 feet in length about 5 inches in width was on the road. I took it to a Mercedes repair shop and they informed me I had a fuel leak and that it was not safe to drive. There was corrosion and rust forming on the tank which seems very odd since the car is garage kept and we don't get much snow in Kentucky. My daughter rides in this car with me and they told me it is very dangerous and needs repaired. If I was to drive over a cigarette we could essentially blow up. I had a second shop look at it and they also informed me I had a fuel leak and would need to replace the fuel tank. I was told there was a recall on some models of Mercedes for this issue but can't seem to find one on my year make and model. Please help with this matter so my daughter and I can remain safe as well as others around us. Seems like we are in a ticking time bomb.

When fuel tank is greater than approximately 3/4 full there is a strong fuel odor that seems to emanate from the rear passenger side of the vehicle; at lesser fuel quantities the odor is not noticeable. On one occasion I detected what appeared to be fuel dripping from underneath the vehicle. Took vehicle to dealership for troubleshooting and was informed "fuel leaks at the fuel pump" and it was recommended that the fuel pump and fuel sender be replaced. Additionally, the leak apparently damaged the electrical wiring harness to the fuel pump and that also needs to be repaired. There were no warning lamps or messages displayed that alerted me to this problem. Obviously, this is a hazard to safety.

The contact's client owns a 2011 Mercedes-Benz C300. The contact stated that the vehicle's owner had complained of an abnormal fuel odor coming from the vehicle. There was no warning light illuminated. Upon inspecting the vehicle, the contact discovered that fuel was spraying out of the fuel pump onto the exhaust. The contact was able to replace the fuel pump and correct the failure. Upon investigation, the contact discovered NHTSA Campaign Number: 12V557000 (Fuel System, Gasoline) which he linked to the failure. The dealer nor the manufacturer had yet to be notified of the failure. The vehicle had been repaired. The failure mileage was approximately 142,000.

I started to smell gas after filling my tank. Once the gas level went down, the odor disappeared. I took car to dealer who said car needs new gas tank (issue on top of tank) and cost is approx $5K for parts and labor. I started reading about same exact issue on same C300 model and year 2011. I was advised that car with high mileage of 114,000 was not worth repairing even though there are no dents, cosmetically very nice, new tires, always dealer maintained. I have the dealer inspection paperwork

The contact owns a 2011 Mercedes-Benz C350. The contact stated that upon approaching the vehicle, he noticed a strong fuel odor. The contact stated as he entered the vehicle, he could still smell the strong gasoline odor. There was no warning light illuminated. The vehicle was taken to the dealer where it was diagnosed that the fuel pump assembly and the fuel filter needed to be replaced. The vehicle was not repaired. The contact referenced NHTSA Campaign Number: 12V557000 (Fuel System, Gasoline). The manufacturer was not notified of the failure. The failure mileage was approximately 52,861.

Every time I fill up the gas tank, I smell gas in the passenger side back seat close to where you pump the gas?

Gas is leaking under the car. Gas dripping location is by the rear passenger tire.

When the fuel tank is full, there is a strong smell of gasoline at the rear of the car. The gasoline odor is extremely strong on the outside, and very strong on the inside. (This is NOT due to overfill or spillage). I searched some Mercedes-Benz blog sites, and discovered others are experiencing similar problems since 2019 to now. The strong gasoline odor can likely pose a health risk. There is also real concern about potential fire or explosion risks.

The contact owns a 2011 Mercedes-Benz C300. The contact stated that after refueling the vehicle and driving a short distance, there was a burning odor coming from inside and outside the vehicle. The traction control warning light was illuminated. The contact had taken the vehicle to a certified mechanic who replaced the fuel cabinet. The burning odor persisted. The contact was informed that the failure was related to NHTSA Campaign Number: 12V557000 (Fuel System, Gasoline) however, the VIN was not included. The manufacturer was made aware of the failure. The approximate failure mileage 12,800.

07/31/2021 Fuel smell in the cabin, and in the garage, and a small paddle of gas formed under the car, but at that time I wasn't sure if it was the A/C condense, or gas. Took car out of the garage and left it there overnight. Drove the car next day and the smell was less noticeable, and it disappeared in about two days. Next two weeks did not ill up the tank completely, and there was no smell or leak. Yesterday, Sunday, Aug 22nd, I filled the car with gas again until the pump stopped, and the smell came back instantly, as I was driving home. Parked the car in the driveway and immediately noticed a large paddle of gas forming under the left rear wheel. Removed back seat and both fuel tank pump metal covers, and both plastic fittings/covers were leaking gas, more so on the driver's side. There are hairline fractures in both covers, and both are leaking gas. Removed both covers and siphoned gas out of the car until the leak stopped. I went to Hendrick's MB of Durham and asked about the recall, they denied that my car qualifies. The parts alone were quoted at $1229.12, without labor, and I was told fuel tank worth about $1,000.00 (without labor) may need to be changed as well. NHTSA recall campaign 2013020002 mentions my car. My defect is worse than most because both sides leak gas, not just the pump, and both have visible with naked eye fractures that leak gas. I cannot understand how is my risk of fire and death while driving less than that of other MB's with exactly the same failure, in the same class, and the same C300, for the same year. I expect the cost of repair with labor to be more than $3,500 .

The contact owns a 2011 Mercedes-Benz C300. The contact stated he started to smell an abnormal fuel odor and noticed a spot where fuel had leaked onto the garage floor. The contact stated that the check engine warning light was illuminated. The contact stated that while inspecting the vehicle, he noticed both fuel tank covers were cracked. The contact drove another vehicle to the local dealer and made them aware of the failure. The vehicle was not diagnosed or repaired. Upon investigation, the contact associated the failure with NHTSA Campaign Number: 12V557000 (Fuel System, Gasoline) however, the VIN was not included. The manufacturer had been informed of the failure. The failure mileage was approximately 82,000.

I suspect a failure in the fuel tank / system seal, which is allowing gas fumes into the cabin. There is a strong smell of gasoline inside the cabin especially after a full tank refill. This issue was also a problem for my 2008 Mercedes Benz E350. It has not been inspected but since my E350 had a similar extended warranty repair, I assume this would be similar. The strong fumes and odor in the cabin is a health risk of breathing the fumes or explosion. There are no warning lamp to indicate this failure. No recalls or extended warranty currently to fix this problem.

CAR INTERIOR SMELLS OF FUEL AFTER FILLING UP THE TANK. THE SMELL IS ALSO NOTICEABLE WHEN PARKED IN THE GARAGE. MY MERCEDES E350 ALSO HAD THE SAME ISSUE AND IT WAS DETERMINED THAT IT WAS A DEFECTIVE FUEL CELL SENDING UNIT.

FILLED GAS TANK FULL START GASOLINE IS LEAKING UNDERNEATH THE VEHICLE - LOCATION REAR PASSENGER SIDE. PLACED A PAN AND COLLECTED APPROXIMATELY A QUART OF GASOLINE IN 4.5 HOURS.

CAR WILL SMELL LIKE FUEL AFTER FILLING UP ON FULL TANK. I TOOK THE CAR INTO MERCEDES OF GREENWAY IN DOWNTOWN HOUSTON. THEY DISCOVERED A LEAK IN FUEL SYSTEM, IT'S CAUSING THE CHECK ENGINE LIGHT TO COME ON BECAUSE OF THE INADEQUATE PRESSURE. WHEN I HAD THE CAR PARKED IN MY GARAGE, MY WHOLE HOUSE SMELLED LIKE FUEL ! IT'S A BIG SAFETY ISSUE/FIRE HAZARD. I'VE SEEN OTHER 2011 C300 ARE EXPERIENCING SAME ISSUES.

PLASTIC TOP OF FUEL PUMP LOCATED UNDER BACK SEAT CRACKS AND FUEL VAPORS ENTER THE CAR. BELIEVE THE PART IS DEFECTED TO CRACK FOR NO REASON OR UNDER STRESS.

STOPPED AT GAS STATION TO GET GAS FOR CAR AS SOON I WAS PUMPING GAS I CAN SMELL & SEE GAS FALLING ON THE FLOOR RIGHT BY THE BACK PASSENGER REAR TIRE. WAITED FOR DRY UP. THEN WENT HOME PARKED CAR CAME BACK OUT SAW A PUDDLE OF GAS WAITED FOR DRY UP. WENT UNDERNEATH AND SAW THE RESIDUE THAT IT HAD LEFT BEHIND AND IT LOOK LIKE IT WAS CRACK FROM THE GAS TANK.