2018 Mercedes-Benz C300 Fuel system Problems
- Complaints
- 10about this part
- Share
- 10%of 99 total for the year
- Median mileage
- 57,150miles
- Trend
- Not enough dataFewer than 15 complaints, too few for a reliable trend.
NHTSA recorded 10 complaints about the fuel system of the 2018 Mercedes-Benz C300, 10% of the 99 complaints for this model year. Where a mileage was given, the median is 57,150 miles.
Fewer than 15 complaints name this part, so treat the figures as a rough indication only.
Example complaints
Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.
“CYLINDER 1 SPARK PLUGS IS DAMAGED DUE TO PISTON DAMAGE, HOLE IN PISTON. IF EXTRA DAMAGE IS FOUND ON TEAR DOWN, COMPLETE ENGINE REPLACEMENT. This is direct from the repair facilities reports. While driving my 2018 C-300 there was smoking out of tail pipe, a rough vibration, hard to control the vehicle and it was starting to lose power. Not a good situation, had to pull over and have vehicle towed to the dealership. Worst part is this is a vehicle used to transport my 5 children to and from school and activities. …”
NHTSA complaint #11446178, filed 2022-01, 62,000 miles“My c300 2018 only has 50k and suddenly the engine light is on, when I check it shows that I need the Positive Crankcase ventilation valve replaced. it cost $2300. As I know a lot of people who own Mercedes have the same problem. Three mechanics claim it on almost all C, CLA, and GLA models. Please make Mercedes recall it finally.”
NHTSA complaint #11533877, filed 2023-07“The engine light is on with only 35000 miles. Upon using an OBD2 scanner, error code P052e positive crankcase ventilation(PCV) malfunction was detected. It's a problem that I researched and noticed a lot of people having the same issue. I was told that this can cause the car to stall or shut down? This causes serious risk and safety issues to drivers, passengers, and pedestrians. With so many complains about this problem, I believe the manufacturer and dealers should take responsibility before tragedies happen.”
NHTSA complaint #11640265, filed 2025-02“This particular model of vehicle has a well-known and documented failure of the PCV valve (Crankcase). This has not been identified by NHTSA to date. This should be considered for a recall due to the high incident rate of the P052E error code (valve failure) as this causes reduced emission control and possible explosions within the engine due to pressure-related issues. My vehicle did not have any warnings prior to the engine light illuminating. After diagnostics, P052E was identified. Dealership told me that it needed to be replaced as it would fail and result in damage.”
NHTSA complaint #11523881, filed 2023-05“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.”
NHTSA complaint #11642176, filed 2025-02, 52,300 milesRelated service bulletins
- 11036999Aug 15, 2026Dear Mercedes-Benz Owner: In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA…
- 11035490Jul 31, 2026This NCU replaces the prior NCU issued on May 15, 2025, and contains additional MY 2023 and MY 2024 vehicles which are highlighted below.
- 11019016May 30, 2025In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA is extending the warranty…
- 11018625May 15, 2025In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA, LLC (“MBUSA”) is…
- 11014402Feb 21, 2025Complaint Customer-perceived problem: • Fuel gauge reading implausible • MIL ON (market-dependent) N118/3 Fault codes in control units FSCM_GEN4/5/6 • For these fault codes, the…
- 11013179Jan 24, 2025Complaint Customer-perceived problem: • Fuel gauge reading implausible • MIL ON (market-dependent) N118/3 Fault codes in control units FSCM_GEN4/5/6 • For these fault codes, the…
- 11031586Aug 20, 2021This NCU replaces the prior NCU issued on July 30, 2021 and includes an additional population (33) of certain MY 2018 Baumusters covered under this extended warranty.
- 10205814Aug 11, 2021Fuel filler flap opens slowly/switch flashes/tank is bleeding instrument cluster warning
- 10144074Mar 2, 2018Update fuel system control unit (FSCU) software
Fuel system: other model years
| Year | Complaints | Share of year |
|---|---|---|
| 2023 | 1 | 5% |
| 2022 | 7 | 28% |
| 2021 | 3 | 21% |
| 2020 | 3 | 9% |
| 2019 | 12 | 17% |
| 2018 | 10 | 10% |
| 2017 | 33 | 15% |
| 2016 | 67 | 23% |
| 2015 | 70 | 18% |
| 2014 | 1 | 1% |
| 2013 | 3 | 1% |
| 2012 | 12 | 4% |
| 2011 | 44 | 9% |
| 2010 | 26 | 6% |
| 2009 | 5 | 1% |
| 2008 | 2 | 0% |
Other parts of the 2018 Mercedes-Benz C300
34 complaintsOther or unknown
23 complaintsBody and structure
14 complaintsSteering
12 complaintsElectrical system
10 complaintsAir bags
4 complaintsForward collision avoidance
4 complaintsVisibility (wipers, defrost, mirrors)
3 complaintsBrakes
2 complaintsExterior lighting
2 complaintsTires
2 complaintsTransmission and drivetrain
2 complaints
← All problems reported for the 2018 Mercedes-Benz C300
About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 31, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.
To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology