Mercedes-Benz C300 fuel leak problems

Filed Oct 27, 2026 · Engine, Fuel system · OH

Hi, in the Fall of 2025 my 2016 Mercedes Benz C300 4 Matic, started giving off smelly fumes while my car was idling/ warming up. I registered a complaint with the Corporate Mercedes Benz Office USA, LLC in April 2026 @ 800‑367‑6372, after the dealership would not correct the issue free of charge. 1. Hose Clamp Replacement problems. 2. The raw fuel leakage produces strong gasoline odors inside the cabin- via the air filter, risk of car stalling and the smell could be leathal. 3. The problem was confirmed in a lawsuit. 4. The dealership would not repair the issue. 5. There were no warning lamps or messages on the dash board, the only essential issue were the smells, fumes, odors and lawsuit.

Filed Sep 12, 2026 · Fuel system · WI

Fuel tank is rusting. Leaking fuel, heavy fuel smell inside cabin. My saftey and anyone around the vehicle would be at risk due to fire chance. Confirmed by independent service center Vehcile has only been inspected by me and the shop Only symptom that appeared was fuel smell in my garage and a puddle of gasoline underneath the vehicle.

Filed May 19, 2026 · Fuel system · MA

Vehicle: 2012 Mercedes-Benz C300 4Matic Sport Problem Component: Fuel / Propulsion System Safety Issue Description: My 2012 Mercedes-Benz C300 developed a serious fuel tank leak at approximately 106,460 miles which created overwhelming gasoline fumes and rendered the vehicle unsafe to operate. The gasoline fumes were extremely strong and entered the passenger area. The fumes were severe enough that I became physically overwhelmed from the gasoline exposure and discarded clothing due to gasoline contamination and odor. A local repair facility identified the leaking fuel tank. I was informed the replacement fuel tank was allegedly on extended backorder through Mercedes-Benz channels. Because the vehicle was unsafe to drive and replacement parts were allegedly unavailable for several months, I was forced to tow the vehicle from [XXX] to [XXX] at my own expense in order to locate a repair facility that could obtain a replacement fuel tank and safely repair the vehicle. The repair invoice states: “Installed used lt fuel tank incl switchover fuel pumps replace section of steel fuel line front of tank from lower braided line.” I am submitting this complaint due to: serious gasoline leak safety concerns, severe gasoline fume exposure, potential fire hazard, and the alleged extended unavailability of replacement fuel tanks. Mercedes-Benz USA Case Number: 22302114 INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed May 15, 2026 · Electrical, Engine · 65,422 miles · CA · fire

The contact owns a 2017 Mercedes-Benz C300. While driving at approximately 15 mph, the contact observed smoke emanating from under the hood. The vehicle was driven to her work location and parked. Upon exiting the vehicle and opening the hood, she observed orange flames coming from the engine compartment. A parking attendant extinguished the fire, and a police and/or fire report was filed. The vehicle was towed to a dealer and diagnosed with a fuel line leak that caused the engine harness to come apart. The leaking fuel hose from the high-pressure fuel pump caused damage to the high-pressure pump, engine harness, vacuum transducer, and coolant feed line from the thermostat to the firewall. The following components needed replacement: high-pressure fuel pump, rubber fuel hose, engine harness, pressure transducer, and intake manifold. The vehicle was repaired. Five months later, the contact experienced another failure she believes was associated with the engine fire. While parked and attempting to start the vehicle, it did not start. The vehicle was towed to a dealer and diagnosed with a faulty starter that needed replacement. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 65,422.

Filed Jan 29, 2026 · Engine, Fuel system · GA

fuel lines/ clamps defective causing a fuel leak. vehicle could catch on fire and fumes are extremely strong inside the cabin. issue confirmed by Mercedes dealer, mentioned there is an extended warranty up to 120,000 miles. rejected mine because i was at 120,300 miles. had to pay out of pocket. no warning lights or anything just the really strong smell of fuel and fuel range dropping. this is a very common issue thats known and should be a recall.

Filed Jan 2, 2026 · Fuel system · 60,000 miles · TX

The contact owns a 2016 Mercedes-Benz C300. The contact stated that whenever the fuel tank was full, there was a fuel-burning odor coming from the engine and entered the vehicle through the A/C vents. In addition, when the vehicle was cold, the odor was entering the vehicle through the A/C vents. No warning lights were illuminated. The vehicle was taken to a collision center specializing in foreign vehicles, where it was diagnosed that the fuel rail and injectors had a fuel leak. The vehicle was not repaired. The contact stated that the failure persisted. Upon further investigation, the contact related the failure to the federal safety agency Campaign Number: 21V961000 (FUEL SYSTEM, GASOLINE). However, the VIN was not included. The contact stated that his mother owned the vehicle in the past and gave the vehicle to the contact two years ago. The contact's mother remembered receiving a recall letter; however, the contact's mother was unsure if the vehicle had been repaired in the past. The manufacturer was made aware of the failure and referred the contact to the NHSTA Hotline for assistance. The failure mileage was approximately 60,000.

Filed Dec 9, 2025 · Fuel system · VA

An independent service center diagnosed my car as having a fuel leak stemming from the fuel rail and fuel injectors. This is a fire hazard due to a gas leak. There is a gas smell in the interior cabin that I noticed approximately one month ago. I believe this pertains to the federal safety agency ID #21V961, and I would like the federal safety agency to consider including my VIN in this recall.

Filed Nov 8, 2025 · Fuel system · TX

Cabin smells heavily like fuel and has a check engine light possibly a fuel leak

Filed Feb 19, 2025 · Fuel system · RI

Fuel tank is leaking at connection between fill tube and tank. Multiple recalls have been issued apparently for similar problems with cars of other years. With less than 1/2 tank, the fuel leak is not as pronounced. With the tank full, the tank drips fuel. Fire department in Riverside was called and confirmed issue. Upon bringing vehicle to Clearwater Mercedes and other mechanics, the problem was confirmed. Dealership says that Mercedes Benz denies that the problem is theirs to resolve. Dealership fixed other issue that was not producing symptoms but stated that the cost to resolve was $5000.00 (about the value of the car at this point).

Filed Feb 14, 2025 · Fuel system · 53,000 miles · NJ

The contact owns a 2016 Mercedes-Benz C300. The contact stated that there was an abnormal fuel odor inside the vehicle when the heater was activated. The contact stated that the cabin air filter was replaced; however, the odor was lingering inside of the vehicle. There was no warning light illuminated. The vehicle was taken to an independent mechanic to be diagnosed and the contact was informed that there was gas leaking onto the transmission and that the fuel rail, fuel hose, and fuel injectors needed to be replaced. The contact referenced the federal safety agency Campaign Number: 21V961000 (FUEL SYSTEM, GASOLINE); as a possible cause for the failure. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 53,000.