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EnginePart report

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 miles

Related service bulletins

Engine: other model years

YearComplaintsShare of year
2024218%
202329%
202228%
2021857%
2020824%
20191725%
20183434%
20177736%
20169432%
201512733%
201422%
201383%
201252%
2011102%
2010133%
2009163%
2008315%

Other parts of the 2015 Mercedes-Benz C300

Fuel system
70 complaints
Other or unknown
63 complaints
Body and structure
60 complaints
Electrical system
50 complaints
Steering
23 complaints
Suspension
22 complaints
Transmission and drivetrain
20 complaints
Visibility (wipers, defrost, mirrors)
16 complaints
Air bags
12 complaints
Brakes
9 complaints
Forward collision avoidance
8 complaints
Wheels
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