2015 Mercedes-Benz C300 Engine Problems
- Complaints
- 127about this part
- Share
- 33%of 381 total for the year
- Median mileage
- 53,000miles
- Trend
- RisingComplaints filed in the last 3 full calendar years are at least 25% higher than in the 3 years before.
NHTSA recorded 127 complaints about the engine of the 2015 Mercedes-Benz C300, 33% of the 381 complaints for this model year. Where a mileage was given, the median is 53,000 miles. 1 a fire, according to the filers.
Example complaints
Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.
“Two issues, purchased a certified pre owned vehicle. At 8900 miles, we noticed the car was idling very rough on a cold start, almost the sound of a diesel. The sound would resolve after 10 minutes of driving. Service informed us that there was a recall on the rods and pistons. We had the engine rebuilt, and the noise is the same, if not worse. The car sounds nothing like laterbuild '15 models or '16 models, nor does it run as smoothly. …”
NHTSA complaint #10825382, filed 2016-02, 8,500 miles“My son's car was blowing white smoke out of the exhaust and had a sweet burning smell and the check engine light came on. The crankcase vent valve is needing to be replaced on this 2015 C300 Mercedes Benz and many owners of this same type of car (different year) are posting about it. Owners of these types of cars are saying that replacement is happening more than once! That it's a common defect of these cars. My son has less than 100,000 miles (61,000 if that) and this shouldn't be happening. And, it's time someone does something to protect the consumer. …”
NHTSA complaint #11513522, filed 2023-03, 61,000 miles“I was in middle line on I-5 SB San Diego doing 40-60MPH when my car suddenly started to shudder, shake and smoke came from the exhaust. The car lost power and the check-engine light came on right away. I was told that Cylinder 3 lost pressure, that the engine wall was damaged and that possibly the piston and wrist pin are cracked. My car has only 66K miles and the Mercedes Benz dealership is telling me that I need a new engine that will cost $19,000. After doing some research I have found out that I wasn't the only one with this issue. …”
NHTSA complaint #11422534, filed 2021-06, 66,000 miles“Car has 51,000 miles , no check engine light or any other warning light .driving in on the freeway at 70 mph when I hear a pop sound and my car loses power , I pushed on the gas and it started to shake violently and I panicked as the construction on the freeway was not allowing drivers a shoulder to pull over on . I was lucky enough to be driving at 2am and with the construction going on , drivers were already slowing down . My car also started blowing a thick white smoke through the back exhaust that could have made it harder to see that late night as it was already foggy here in California . …”
NHTSA complaint #11450360, filed 2022-02, 51,000 miles“In March of 2020 I was driving home from work. I stopped at a red light. When it turned green, I proceeded to step on the gas. My car started making noises and shaking as I drove. My check engine light came on. I was able to pull over without incident. My vehicle has under 48k miles on it! I had it towed to a Firestone facility by my house. They replaced spark plugs and ignition coil 1 and 2. They said it was still severely misfiring. Cylinder 1 must have internal damage and should be towed to the dealer. They gave me a spark plug they removed that had significant damage to the top part. …”
NHTSA complaint #11423487, filed 2021-07, 48,000 milesRelated 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…
- 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…
- 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…
- 11031589Jul 9, 2024This NCU replaces the prior NCUs issued on August 25, 2023, August 31, 2023 respectively and, contains clarification on parts ordering.
- 11005276Jul 8, 2024Complaint Check engine light illuminated Fault code stored in N3/10 control unit- P052E71 – Positive Crankcase Ventilation Regulator Valve Performance: The valve for crankcase…
- 11000623May 14, 2024Complaint Check engine light illuminated Fault code stored in N3/10 control unit- P052E71 – Positive Crankcase Ventilation Regulator Valve Performance: The valve for crankcase…
- 11031729Mar 20, 2019The purpose of this letter is to advise you of additional benefits that Mercedes-Benz is providing to you regarding your vehicle ownership.
- 11031616Mar 13, 2019Daimler AG (“DAG”), the manufacturer of Mercedes-Benz vehicles, has determined that on the various Model Year (“MY”) 2014 - 2018 Mercedes-Benz vehicles listed below, the engine…
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 2015 Mercedes-Benz C300
70 complaintsOther or unknown
63 complaintsBody and structure
60 complaintsElectrical system
50 complaintsSteering
23 complaintsSuspension
22 complaintsTransmission and drivetrain
20 complaintsVisibility (wipers, defrost, mirrors)
16 complaintsAir bags
12 complaintsBrakes
9 complaintsForward collision avoidance
8 complaintsWheels
8 complaints
← All problems reported for the 2015 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