IsItAGoodCar

Common Problems with the
2011–2018 Mercedes-Benz B-Class (W246)

We've identified 3 known issues that can affect the 2011–2018 Mercedes-Benz B-Class (W246). None are considered critical, but they're worth knowing about before you buy.

3
Known Issues
0
Serious
3
Moderate
0
Minor

All Known Issues

7G-DCT Gearbox Judder

ModerateGearbox & Transmission

The dual-clutch automatic can become hesitant or jerky if clutch wear is present or fluid changes have been skipped.

Most affected: B 180 d Auto, B 200 Auto, B 220 d Auto

Estimated cost: £400–£1,500Affects: 2011–2018

Typical symptoms

  • •Shuddering when pulling away
  • •Delay engaging reverse

What to inspect before you buy

  • ✓Test drive in slow-moving traffic
  • ✓Check service history for DCT fluid changes

OM651 Diesel Timing Chain Tensioner Oil Leak

ModerateEngine

The gasket on the timing chain tensioner is a frequent leak point. Oil loss can reduce tensioner pressure and lead to chain rattle and eventual stretch.

Most affected: B 180 d, B 200 d, B 220 d

Estimated cost: £200–£500Affects: 2011–2018Often appears around: 50,000–90,000 miles

Typical symptoms

  • •Oil leak on the right side of the engine block
  • •Burning oil smell
  • •Rattle on cold start

What to inspect before you buy

  • ✓Inspect the area around the tensioner for fresh oil
  • ✓Listen for chain rattle during a cold start

Water ingress in boot from rear air vent seals

ModerateElectrics & Electronics

The rear air vent seals behind the bumper can fail, allowing water into the boot. This can damage the rear SAM electrical module, causing lighting and locking faults.

Estimated cost: £100–£500Affects: 2011–2018Often appears around: Age-related

Typical symptoms

  • •Damp or wet boot floor
  • •Random rear light faults
  • •Boot locking issues

What to inspect before you buy

  • ✓Inspect the spare wheel well for damp
  • ✓Check the rear vent seals behind the bumper
  • ✓Test all rear lights and central locking

Buying Tips for the 2011 Mercedes-Benz B-Class (W246)

  • ✓Check the 7G-DCT gearbox for juddering in stop-start traffic; fluid changes every 3 years/31,000 miles are vital
  • ✓Look out for water ingress in the boot, often caused by failing rear air vent seals behind the bumper
  • ✓Ensure the diesel variants (if mainly used in town) have no AdBlue or DPF warnings

Browse 2011–2018 Mercedes-Benz B-Class (W246) in our Directory

View MOT history, registration data, and reliability scores for 2011–2018 Mercedes-Benz B-Class (W246) vehicles.

View 2011–2018 Directory

Other Mercedes-Benz B-Class (W246) Year Periods

2011–2018

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