Used car guide · 2005–2026

Mercedes-Benz B-Class common problems and MOT failures

What goes wrong on a used Mercedes-Benz B-Class, year by year: known faults from UK buying guides, the parts flagged at MOT more than on other cars (from 202,969 MOTs done during 2023–2025), and what to check before you buy one.

202,969MOTs done in 2023–2025, all years of this model
72,013on the UK register
3known faults across all years
2013best year at its MOT

Pick the year

Most years have their own guide. The year is when the car was first registered (it’s on the logbook, or check the reg below).

2026202520242023202220212020201920182017201620152014201320122011201020092008200720062005

What usually goes wrong with a Mercedes-Benz B-Class?

Known faults reported by owners, mechanics and UK buying guides, in our own words. Most apply to certain years or engines only, so check which the car has.

  • Many recalls (21)

    Cars registered 2012–2019 · All engines

    Recalls covered automatic gearbox faults, rear seat backrests, engine failures (2015), fuel leaks, brakes, airbags, air con, adaptive cruise and headlights stuck on main beam.

    At the viewing: Ask a Mercedes dealer to check the VIN for outstanding recalls.

    Source: Auto Express: used Mercedes B-Class (Mk2, 2011-2019) review

  • Dual-clutch gearbox surging

    Cars registered 2012–2019 · Automatic

    The dual-clutch automatic can surge and lose drive.

    At the viewing: Drive in slow traffic and pull away several times.

    Source: Auto Express: used Mercedes B-Class (Mk2, 2011-2019) review

  • Starter motor wear

    Cars registered 2012–2019 · Cars with stop-start

    The stop-start system can shorten the starter motor’s life.

    At the viewing: Listen for a slow or noisy restart at junctions.

    Source: Auto Express: used Mercedes B-Class (Mk2, 2011-2019) review

Common Mercedes-Benz B-Class MOT failures to check

Parts flagged at MOT well above the usual rate for cars the same age, in more than one year. From the DVSA’s results for every MOT done in Great Britain during 2023–2025.

  • Link ball joint covers

    up to 5.6× usual

    Stands out on cars registered in 2009, 2010, 2011, 2012, 2013, 2014, 2015 and 2016.

    Rough price £60–£150 (one joint) ClickMechanic

    At the viewing: Listen for knocking over bumps and check the rubber boots behind the wheels aren't split.

  • Rigid brake pipes

    up to 3.6× usual

    Stands out on cars registered in 2006, 2007, 2008, 2009, 2010, 2011 and 2012.

    Rough price £100–£400 our estimate

    At the viewing: Ask to see underneath, or check the MOT advisories: corroded brake or fuel pipes get worse every year and fail the MOT when they do.

  • Corroded fuel pipes

    up to 11.7× usual

    Stands out on cars registered in 2005, 2006, 2007, 2008, 2009 and 2011.

    Rough price £100–£400 our estimate

    At the viewing: Ask to see underneath, or check the MOT advisories: corroded brake or fuel pipes get worse every year and fail the MOT when they do.

  • Drive shaft (CV) joints

    up to 3.4× usual

    Stands out on cars registered in 2005, 2006, 2007, 2008, 2009 and 2010.

    Rough price £60–£350 our estimate

    At the viewing: Drive slowly on full steering lock in both directions and listen for clicking. Look for split rubber boots behind the front wheels.

  • Individual direction indicators

    up to 2.6× usual

    Stands out on cars registered in 2005, 2006, 2010 and 2011.

    Rough price £10–£80 our estimate

    At the viewing: Ask a friend to check every light while you work the switches: indicators, brake lights, fog lights and reversing lights.

  • Washers

    up to 2.3× usual

    Stands out on cars registered in 2005, 2006, 2007 and 2008.

    Rough price £15–£60 our estimate

    At the viewing: Test the wipers and washers on every speed.

Mercedes-Benz B-Class MOT pass rate by year

Of the years since 2005 with plenty of MOT tests, the 2013 Mercedes-Benz B-Class did best (73% passed first time, 6 points above all 2013 cars) and the 2011 did worst (60%, 2 points below all 2011 cars). Older cars fail more, so compare each year with all cars registered the same year.

YearPass first timeAll cars that yearMOT tests
202291%89% +21,424
202191%87% +43,631
202091%87% +48,747
201989%85% +41,758
201885%83% +211,521
201782%80% +216,941
201681%77% +415,928
201578%74% +416,859
201474%70% +424,593
201373%67% +621,133
201270%64% +617,251
201160%62% -210,635
201059%60% -113,626
200958%59% -113,002
200855%57% -210,481
200756%57% -18,076
200656%56% +06,099
200556%57% -11,264

Questions to ask the seller before buying a Mercedes-Benz B-Class

Ask before you travel to see it. A seller who knows the car will have answers, and receipts.

  1. Have all the recalls been done? Can a Mercedes dealer confirm from the VIN?
  2. Any recent work on the link ball joint covers? (Flagged at MOT 5.6× as often on the Mercedes-Benz B-Class as on other cars the same age.)
  3. Any recent work on the rigid brake pipes? (Flagged at MOT 3.6× as often on the Mercedes-Benz B-Class as on other cars the same age.)
  4. Any recent work on the corroded fuel pipes? (Flagged at MOT 11.7× as often on the Mercedes-Benz B-Class as on other cars the same age.)
  5. Can I see the service history and receipts for any big jobs?

Looking at a Mercedes-Benz B-Class?

Check the actual car: its own MOT history, whether it already shows these weak spots and what to ask the seller. Free, no sign-up.

Where this comes from: MOT figures are the DVSA’s anonymised results for every MOT test done in Great Britain during 2023–2025, grouped by the year each car was first registered. How many are on the road is from the Department for Transport’s vehicle licensing statistics. Known faults are from UK buying guides, in our own words, with links. How we score