IsItAGoodCar

Common Problems with the
2009–2012 Mercedes-Benz C-Class (W204)

We've identified 3 known issues that can affect the 2009–2012 Mercedes-Benz C-Class (W204). 2 of these are serious faults that could be expensive to repair.

3
Known Issues
2
Serious
1
Moderate
0
Minor

The 2009–2012 period has 2 more issues than the Mercedes-Benz C-Class (W204) average across all year periods.

All Known Issues

Rear Subframe Corrosion

SeriousSuspension & Chassis

The rear subframe rots from the inside out, leading to MOT failure. Mercedes often replaces these under goodwill.

Estimated cost: £0 (Goodwill) – £1,500Affects: 2007–2014

Typical symptoms

  • •Heavy corrosion noted by MOT
  • •Rust on suspension mounts

What to inspect before you buy

  • ✓Request a subframe inspection at a main dealer

Electronic Steering Lock (ESL) failure

SeriousElectrics & Electronics

The electronic steering lock module can fail, preventing the car from starting. The key is recognised but the steering remains locked. A common and expensive fault on W204s built before the facelift.

Most affected: All pre-facelift models

Estimated cost: £400–£1,200Affects: 2007–2012Often appears around: 60,000–100,000 miles

Typical symptoms

  • •Key recognised but engine won't crank
  • •Steering lock warning on dash
  • •Intermittent no-start conditions

What to inspect before you buy

  • ✓Test start-up from cold
  • ✓Check for "Steering Lock Defective" messages
  • ✓Ask if the ESL has been replaced

OM651 Diesel Chain Tensioner Oil Leak

ModerateEngine

The gasket on the timing chain tensioner can fail, leaking oil and potentially leading to timing chain issues due to inconsistent tension.

Most affected: C 200 CDI, C 220 CDI, C 250 CDI

Estimated cost: £200–£450Affects: 2009–2014Often appears around: 50,000–100,000 miles

Typical symptoms

  • •Oil leaking onto the right side of the engine block
  • •Rattle on cold start

What to inspect before you buy

  • ✓Check the side of the engine block for oil dampness
  • ✓Listen for chain noise on a cold start

Buying Tips for the 2009 Mercedes-Benz C-Class (W204)

  • ✓Inspect the rear subframe very carefully; ask about Mercedes goodwill replacement.
  • ✓Listen for steering lock (ESL) failure signs.
  • ✓M271 petrols need timing chain checks.
2007–2008 Mercedes-Benz C-Class (W204)2013–2014 Mercedes-Benz C-Class (W204)

Browse 2009–2012 Mercedes-Benz C-Class (W204) in our Directory

View MOT history, registration data, and reliability scores for 2009–2012 Mercedes-Benz C-Class (W204) vehicles.

View 2009–2012 Directory

Other Mercedes-Benz C-Class (W204) Year Periods

2007–20082009–20122013–2014

Looking at a specific 2009 Mercedes-Benz C-Class (W204)?

Enter the registration number to check its full MOT history, outstanding finance, write-off status, and more.

Free Vehicle Check