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.

The 2023 Mercedes-Benz B-Class

Cars registered in 2023 haven’t had their first MOT yet (it’s due at 3 years old), so there are no MOT results to show. There are no known faults on record for this year in the UK buying guides we use, so the rest of this page covers the Mercedes-Benz B-Class as a whole.

785on the UK register at the end of 2025
2026first MOT due
Dieselmost common fuel (also petrol)
What to check on a 2023 car
  • Warranty left

    Ask for the date it was first registered and check how much of the maker’s warranty is left, and that it transfers to you. Electric and hybrid batteries usually have a longer, separate warranty.

  • Servicing

    Servicing on time with the maker’s schedule keeps the warranty valid. Ask for the service book or the dealer’s digital record.

  • Finance

    Nearly new cars are often still on finance. A history check shows outstanding finance, and whether it has been written off or stolen.

  • Recalls

    Ask whether any recall work has been done, and check the reg on GOV.UK’s free recall checker.

  • Logbook (V5C)

    The name and address should match the seller, and the VIN on the V5C should match the car.

Check for recalls on GOV.UK

Other years

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, for each fuel on its own. From the DVSA’s results for every MOT done in Great Britain during 2023–2025.

Petrol

  • Link ball joint covers

    up to 3.9× usual

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

    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.

  • Drive shaft (CV) joints

    up to 3.3× usual

    Stands out on cars registered in 2005, 2006, 2007, 2008, 2009, 2010 and 2011.

    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.

  • Rigid brake pipes

    up to 3.3× usual

    Stands out on cars registered in 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 8.2× usual

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

    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.

  • Side repeaters

    up to 6.3× usual

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

    Rough price £10–£80 our estimate

    At the viewing: Ask a friend to check every light, including brake lights and indicators, while you operate them.

  • Individual direction indicators

    up to 2.5× usual

    Stands out on cars registered in 2006, 2007, 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.

Diesel

  • Rigid brake pipes

    up to 4.1× usual

    Stands out on cars registered in 2005, 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 13.7× usual

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

  • Link ball joint covers

    up to 6× usual

    Stands out on cars registered in 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.

  • Drive shaft (CV) joints

    up to 4.1× usual

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

    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.

  • Wheels

    up to 2.8× usual

    Stands out on cars registered in 2012, 2013, 2014 and 2018.

    Rough price £70–£150 our estimate

    At the viewing: Check the tread on all four tyres, including the inside edges, and look for cracks or bulges.

  • Number plate lights

    up to 4.1× usual

    Stands out on cars registered in 2016, 2017 and 2018.

    Rough price £5–£40 our estimate

    At the viewing: Check the number plate lights work and the plates are clean and legal.

Electric

  • Link ball joint covers

    up to 14× usual

    Stands out on cars registered in 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.

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