Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2010 Mercedes-Benz C300 owners, lightly cleaned up (personal details are redacted by NHTSA).
Filled up gas and strong gas smell can be smelt throughout the car and Check engine light came on, took car to auto zone for report. Stated emissions code was listed. Was told to replace gas cap and code should clear. Replaced gas cap, still had code. Took car to shop and was told this model has this issue with this specific year and newer, and the problem could be one of 3 things. Replace gas cap, did that, replace fuel pump closing cover, did that, replace purge valve canister, did that. Check engine light still comes on and strong gas smell still exist after each fill up. Mechanic told me reach out because there was a recall on this same model a few years back...
Our 2010 Mercedes C300 with 24,500 miles car started to sell gasoline appx a week ago. We found out that Mercedes has similar problems with their other cars and I believe this is a very serious problem since it involves gasoline. The Mercedes dealer stated that our car does not have a recall for this problem even though it has the same problem as the other recalled models. The smell is constant and we cannot even park our car in our garage due to the fumes and strong smell. Mercedes of palm spring like to charge us $256 just to look at the car so we took our car to another repair shop and they stated that the fuel tank has a problem as the other models and our car is the 3rd merdeces that they inspected with the same problem that week. At this time Mercedes is refusing to repair this on a warranty and as I stated this is a safety issue. I believe this is a very serious safety issue.
Tl* the contact owns a 2010 Mercedes-Benz C300. A few years ago, the contact detected a fuel odor coming from the vehicle. The vehicle was taken to Mercedes-Benz of foothill ranch (81 auto center dr, foothill ranch, ca 92610, [phone]) where it was diagnosed that the rear passenger side fuel fender seal/ seal ring failed. The vehicle was repaired, but the odor recurred. The vehicle was taken back to the same dealer where it was diagnosed that the fuel filter housing was leaking and the rear padding and lower seat cushion were saturated with fuel and needed to be replaced. The contact stated that the entire rear seat was replaced. The vehicle was repaired. The manufacturer was notified of the failure and did not assist. The approximate failure mileage was 108,989.
Tl* the contact owns a 2010 Mercedes-Benz C300. While driving, the engine warning indicator illuminated and a fuel odor entered the vehicle. The vehicle was taken to Mercedes-Benz of south mississippi (11619 bobby eleuterius blvd, d'iberville, ms 39540), but the failure could not be duplicated. Days later, the failure persisted. The vehicle was taken back to Mercedes-Benz of south mississippi, but the cause of the failure could not be diagnosed. The vehicle was not repaired. The vehicle was taken to an independent mechanic where they informed the contact that there was liquid gas formed on top of the fuel pump and a seal needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 70,000.
Tl* the contact owns a 2010 Mercedes Benz C300. The contact stated that for the past month, a fuel odor inside the cabin developed. The contact noticed a wet spot on the driveway and upon inspection did not find where the fuel was leaking from. The vehicle was taken to caliber motors Mercedes Benz of anaheim california and the diagnosis was that the passenger side side fuel sending unit cover and seal were worn out and needed replacement. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 70,000. The VIN was not available.
Tl* the contact owns a 2010 Mercedes Benz C300. Upon entering the vehicle, there was a fuel odor coming from the fuel tank. The failure occurred on several occasions. The vehicle was taken to an independent mechanic where it was diagnosed that the fuel filter was cracked. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 65,000. The VIN was not available.
Strong gasoline smell when I fill my tank up and park my car inside my garage. So strong that I worry about explosion due to my water heater with pilot light in the garage. I frequently open the garage door to let the accumulated gas odor dissipate or have to move the car outside. Strong gasoline smell goes away once the fuel level goes down about 1/8 to 1/4. This has been going on since 12/20/2020.
The check engine light comes on dealing with the catalytic converter/fuel system. The sensors are off causing the emission of too much gas. The car runs out of gas fast and does not drive well to get good gas miles per tank. The car's exterior lights also go out fast. This should not happen with a top of the line Mercedes car.
Strong smell of gasoline when tank is filled up. This has been an ongoing issue for a few months now. Don't know much about cars so didn't think much of it until I had a couple of people ask why my car smelled like gas. They let me know that it May be a gas leak somewhere.
Fuel leaking into main cabin. Pool of fuel resting on top of the fuel sending unit located under passenger rear seat. Draining into back of seat area. Particularly noticeable upon new filling of tank or driving on curvy roads.
Fuel System complaints in other C300 years
Frequently asked questions
How common are fuel system problems on the 2010 Mercedes-Benz C300?
NHTSA has 26 complaints about the fuel & propulsion system of the 2010 Mercedes-Benz C300, 6% of the model year's 453 complaints.
Is there a recall for 2010 Mercedes-Benz C300 fuel system problems?
No. NHTSA lists no fuel & propulsion system recall for the 2010 Mercedes-Benz C300, though it has 6 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2010 Mercedes-Benz C300 fuel system problems start?
Half of the complaints with a recorded mileage happened before about 70,000 miles, and 7% before 25,000 miles.
Is it dangerous?
Owners linked 1 crash, 0 fires and 0 injuries to fuel & propulsion system problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.