2018 Mercedes-Benz C300 Engine Problems
- Complaints
- 34about this part
- Share
- 34%of 99 total for the year
- Median mileage
- 14,000miles
- Trend
- RisingComplaints filed in the last 3 full calendar years are at least 25% higher than in the 3 years before.
NHTSA recorded 34 complaints about the engine of the 2018 Mercedes-Benz C300, 34% of the 99 complaints for this model year. Where a mileage was given, the median is 14,000 miles.
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“My vehicle only had 31,000 miles and I experienced engine failure. I bought a new engine for 16, 500. 00 dollars. Mercedes Benz did nothing. I almost got in to several accidents because the engine completely stop on the interstate. Almost got hit by several cars. This is unacceptable.”
NHTSA complaint #11695170, filed 2025-10“CRACKED PISTON AT 68K MILES The vehicle is very well maintained, only 68k miles, has had every oil change, only takes premium gas. I was driving it when the check engine light went on and the vehicle began shaking violently. After towing the vehicle to the Mercedes Benz dealership, they informed me that the piston cracked and they could not articulate a reason why this would happen.”
NHTSA complaint #11478301, filed 2022-08“Engine light P052E, This seems to be a common problem with the C300.My concern is that Mercedes Benz hasn’t address the common issue. I own the car less than a year got it from Mercedes dealership and to be honest I expect Mercedes Benz to be better than the this to it customers”
NHTSA complaint #11508602, filed 2023-02Related service bulletins
- 11034064Jun 19, 2026Dear Mercedes-Benz USA Dealers, The part numbers listed in the chart below should no longer be installed, and any existing stock must be returned to your facing PDC. The deadline…
- 11030302Mar 27, 2026Complaint -Check engine light illuminated. -Engine runs rough. -Poor shifting or jerking when accelerating. -Fault codes stored related to mixture formation, injector quantity…
- 11028267Feb 2, 2026Complaint -Check engine light illuminated. -Engine runs rough. -Poor shifting or jerking when accelerating. -Fault codes stored related to mixture formation, injector quantity…
- 11018530May 15, 2025Complaint Check engine light illuminated Fault code stored in N3/10 control unit- P052E71 – Positive Crankcase Ventilation Regulator Valve Performance: The valve for crankcase…
- 11008712Oct 4, 2024Complaint Check engine light on. One of the below fault codes is current in the engine control module (N3/10). P04DB29, P04DB31, P04DB79 Cause Open circuit or high resistance to…
- 11008056Sep 16, 2024Complaint Check engine light on. Fault code P207273 - "Throttle actuator valve is blocked due to ice" stored. Engine may crank and not start. Fault code P210185 may also be…
- 11031806Aug 9, 2024In our continuing efforts to assure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA (“MBUSA”) is extending…
- 11008064Aug 9, 2024In our continuing efforts to ensure the proper performance and quality of your vehicle, we are writing to inform you that on certain Model Year 2011-2018 C-Class, E-Class…
- 11005314Jul 20, 2024Complaint Yellow Coolant warning comes on in cluster Fault codes below are current or stored in MED41 P0A0500- The actuation of the circulation pump for the low-temperature…
- 11005313Jul 17, 2024Complaint Check engine light on and fault code P019185 current or stored in MED41 control unit. Adaptation and misfire faults may also be stored. Vehicle may enter limp home…
Engine: other model years
| Year | Complaints | Share of year |
|---|---|---|
| 2024 | 2 | 18% |
| 2023 | 2 | 9% |
| 2022 | 2 | 8% |
| 2021 | 8 | 57% |
| 2020 | 8 | 24% |
| 2019 | 17 | 25% |
| 2018 | 34 | 34% |
| 2017 | 77 | 36% |
| 2016 | 94 | 32% |
| 2015 | 127 | 33% |
| 2014 | 2 | 2% |
| 2013 | 8 | 3% |
| 2012 | 5 | 2% |
| 2011 | 10 | 2% |
| 2010 | 13 | 3% |
| 2009 | 16 | 3% |
| 2008 | 31 | 5% |
Other parts of the 2018 Mercedes-Benz C300
23 complaintsBody and structure
14 complaintsSteering
12 complaintsElectrical system
10 complaintsFuel 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 30, 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