2009 Mercedes-Benz C63 Engine Problems
- Complaints
- 2about this part
- Share
- 17%of 12 total for the year
- Median mileage
- 44,320miles
- Trend
- Not enough dataFewer than 15 complaints, too few for a reliable trend.
NHTSA recorded 2 complaints about the engine of the 2009 Mercedes-Benz C63, 17% of the 12 complaints for this model year. Where a mileage was given, the median is 44,320 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.
“Cel illumination, engine misfire, stalling, rough running, low coolant indicator light ups. No external coolant loss detectable. Coolant in the engine oil and/or in the combustion chamber. This is caused by a broken cylinder head bolt. Engine coolant enters into engine oil. Coolant might be present in the combustion chamber. Affected engine number up to 1569xx 60 060658. Now the dealership is trying to charge me $7k to have this fixed when it's a known issue on these vehicles. I respectfully demand that mercedes benz USA cover the costs and recall these affected bolts asap.”
NHTSA complaint #10716413, filed 2015-05, 45,000 miles“The vehicle experienced a headbolt failure resulting in coolant flooding one of the cylinder, leaking inside the engine and causing engine failure. I was lucky that I was driving at 20mph at the time of the failure, otherwise it would most likely result in a crash. Mercedes-benz USA denies the widespread nature of the problem affecting all of the m156 engines, even through in 2010 Mercedes-Benz issued a service bulletin directing replacement of the headbolts with the new improved design and I personally know 3 other owners whose vehicle experienced exactly the same problem. …”
NHTSA complaint #10579288, filed 2014-04, 43,639 milesRelated service bulletins
- 11017039Apr 1, 2025Complaint Vehicle with atypical reduced heat output. Cause Silicate granulate may have escaped from a damaged bag in the expansion reservoir (not visible), reducing the coolant…
- 10153992Dec 3, 2018C63/GTx 177/178 Check Engine Light on with Misfire DTC's. Engine Running Roughly
- 10151939Jul 12, 2018C63/GTx 177/178 Check Engine Light on with Misfire DTC's. Engine Running Roughly
- 10158329Oct 9, 2017Oil in engine wiring harness
- 10205150Nov 7, 2016Engine sound change after recent software updates.
Engine: other model years
| Year | Complaints | Share of year |
|---|---|---|
| 2009 | 2 | 17% |
Other parts of the 2009 Mercedes-Benz C63
4 complaintsElectrical system
4 complaintsExterior lighting
2 complaintsBrakes
1 complaintsEngine cooling
1 complaintsVisibility (wipers, defrost, mirrors)
1 complaints
← All problems reported for the 2009 Mercedes-Benz C63
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