2012 Mercedes-Benz C300 problems & reliability
264 owner complaints filed with NHTSA for the 2012 Mercedes-Benz C300, alongside 6 safety recall campaigns. Last verified Aug 7, 2026. Complaints are unverified reports submitted by owners to the federal Office of Defects Investigation.
Each complaint is counted once (by NHTSA case number), even when it names several vehicles.
5 complaints report injuries (6 injured, 1 deaths reported).
Most reported problems
| Component | Complaints | Share |
|---|---|---|
| Air Bags | 114 | 43% |
| Suspension | 68 | 26% |
| Structure | 54 | 20% |
| Unknown OR Other | 23 | 9% |
| Electrical System | 12 | 5% |
| Service Brakes | 12 | 5% |
| Fuel/propulsion System | 8 | 3% |
| Steering | 8 | 3% |
| Engine | 5 | 2% |
| Power Train | 5 | 2% |
Component groups as classified by NHTSA. A complaint can name more than one component, so shares may sum to more than 100%.
Common symptoms owners describe
Keyword analysis of complaint narratives; one complaint can describe several symptoms.
Mileage when problems occurred
Half of the failures with a reported odometer reading occurred by 85,000 miles (middle 50% between 52,880 and 115,000 miles), based on 73 complaints that included mileage.
Complaints by incident year
What owners report
“Vehicle: 2012 Mercedes-Benz C300 4Matic Sport Problem Component: Fuel / Propulsion System Safety Issue Description: My 2012 Mercedes-Benz C300 developed a serious fuel tank leak at approximately 106,460 miles which created overwhelming gasoline fumes and rendered the vehicle unsafe to operate. The gasoline fumes were…”
Fuel/propulsion System · filed May 19, 2026
“I have a rust free, relatively lower mileage car I bought for my teen daughter. Despite being such a clean car the rear subframe has rusted and rear suspension has broke off while driving, hitting the fuel tank and is unstable. We avoided an accident but the car is not drivable.”
Suspension · filed Apr 19, 2026
“Mercedes of Danbury replaced the rear sub frame CODE 3441 47, since my mechanic (Newtown Auto Repair) told me that the Front subframe is in real bad shape, rotten/rusted, that it is dangerous to drive the car in this condition since the wheel and steering components are part and attached to it, the car would be out of…”
Structure · filed Nov 24, 2025
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Federal defect investigations
- Desiccated Air Bag Inflator Rupture
Engineering Analysis EA21002 · opened Sep 17, 2021 · open
Technical service bulletins
101 manufacturer communications (TSBs, service campaigns, warranty extensions) are on file with NHTSA for the 2012 Mercedes-Benz C300. The 10 most recent:
Single throttle lift-off clunking noise from the side shaft when moving off (audible at the outboard end). The noise is heard once in each instance when changing direction of travel. Note: Sound file in attachment Cause…
LI35.30-P-058566 · Service Bulletin/Repair Instructions · issued Jul 14, 2026
Complaint Creaking noise, in irregular sequence when driving slowly in combination with slight steering movements and/or Creaking/crackling noises from the area of the wheel bearing on the front axle when cornering/…
LI33.20-P-078406 · Service Bulletin/Repair Instructions · issued Jul 7, 2026
Complaint There are several types of complaint about noises or poor windshield wiper wiping performance: A: Wiper blades squeaking, chattering, shuddering B: The windshield is not wiped completely (streaking) C: During…
LI82.30-P-059239 · Service Bulletin/Repair Instructions · issued May 19, 2026
Complaint Potential corrosion on the rear axle carrier Cause Due to market-specific conditions such as moisture, ingress of dirt and/or environmental influences, corrosion can occur on the rear axle carrier Remedy In…
LI35.10-P-078931 · Service Bulletin/Repair Instructions · issued May 13, 2026
Complaint Creaking noise, in irregular sequence when driving slowly in combination with slight steering movements and/or Creaking/crackling noises from the area of the wheel bearing on the front axle when cornering/…
LI33.20-P-078406 · Service Bulletin/Repair Instructions · issued May 12, 2026
Complaint Headlamp, front fog lamp leaky or fogged. Cause Fogging of the headlamps is a natural phenomenon, which can occur under certain climatic conditions. It does not lead to any technical impairment of the…
LI82.10-P-078301 · Service Bulletin/Repair Instructions · issued Apr 16, 2026
Complaint Headlamp, front fog lamp leaky or fogged Cause Fogging of the headlamps is a natural phenomenon, which can occur under certain climatic conditions. It does not lead to any technical impairment of the headlamp…
LI82.10-P-078301 · Service Bulletin/Repair Instructions · issued Mar 9, 2026
Complaint Headlamp, front fog lamp leaky or fogged Cause Fogging of the headlamps is a natural phenomenon, which can occur under certain climatic conditions. It does not lead to any technical impairment of the headlamp…
LI82.10-P-078301 · Service Bulletin/Repair Instructions · issued Feb 24, 2026
Complaint Single throttle lift-off clunking noise from the side shaft when moving off (audible at the outboard end). The clunk is heard once when changing from forward to reverse (and vice versa). Note: Sound file in…
LI33.30-P-056665 · Service Bulletin/Repair Instructions · issued Nov 15, 2025
Complaint Single throttle lift-off clunking noise from the side shaft when moving off (audible at the outboard end). The clunk is heard once when changing from forward to reverse (and vice versa). Note: Sound file in…
LI33.30-P-056665 · Service Bulletin/Repair Instructions · issued May 21, 2025
TSBs are repair guidance manufacturers send to dealers — they are not recalls and repairs are not automatically free. Full documents are available on NHTSA’s site.
Safety recalls
The 2012 Mercedes-Benz C300 has 6 NHTSA recall campaigns — recall repairs are free at franchised dealers regardless of the vehicle’s age.
Check whether your specific vehicle is affected
Recall campaigns often cover only certain VIN ranges. Enter your VIN on the official NHTSA site to confirm whether your vehicle is included and whether the repair is still open.
Check VIN on NHTSA →Buying a used 2012 Mercedes-Benz C300?
- · Decode the seller’s VIN with our free VIN decoder to confirm the exact year, engine and trim.
- · Check for unrepaired recalls by VIN on NHTSA’s official lookup — recall repairs are free.
- · Owners most often reported problems around 85,000 miles — budget accordingly if the car is approaching that mileage.