Used car guide · 2017–2020

Mercedes-Benz X-Class common problems and MOT failures

What goes wrong on a used Mercedes-Benz X-Class, year by year: known faults from UK buying guides, the parts flagged at MOT more than on other cars (from 3,704 MOTs done during 2025), and what to check before you buy one.

3,704MOTs done in 2025, all years of this model
2020best 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).

2020201920182017

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

We haven’t found widely reported faults for the Mercedes-Benz X-Class in the UK buying guides we use yet. That doesn’t mean it has none, so check the car carefully and look at the MOT weak spots below.

Common Mercedes-Benz X-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 2025.

  • Anti-roll bar bushes and joints

    up to 35× usual

    Stands out on cars registered in 2018 and 2019.

    Rough price £100–£280 (pair of drop links) Checkatrade

    At the viewing: Drive slowly over bumps and listen for a knock or rattle from the front. Worn anti-roll bar links are a cheap fix.

  • Engine warning light

    up to 4.6× usual

    Stands out on cars registered in 2018 and 2019.

    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.

  • Number plate lights

    up to 3.9× usual

    Stands out on cars registered in 2018 and 2019.

    Rough price £5–£40 our estimate

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

Mercedes-Benz X-Class MOT pass rate by year

Of the years since 2005 with plenty of MOT tests, the 2020 Mercedes-Benz X-Class did best (86% passed first time, 0 points above all 2020 cars) and the 2019 did worst (81%, 3 points below all 2019 cars). Older cars fail more, so compare each year with all cars registered the same year.

YearPass first timeAll cars that yearMOT tests
202086%86% +0666
201981%84% -31,626
201880%81% -11,257
201777%78% -1155 (small sample)

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

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

  1. Any recent work on the anti-roll bar bushes and joints? (Flagged at MOT 35× as often on the Mercedes-Benz X-Class as on other cars the same age.)
  2. Any recent work on the engine warning light? (Flagged at MOT 4.6× as often on the Mercedes-Benz X-Class as on other cars the same age.)
  3. Any recent work on the number plate lights? (Flagged at MOT 3.9× as often on the Mercedes-Benz X-Class as on other cars the same age.)
  4. Can I see the service history and receipts for any big jobs?

Looking at a Mercedes-Benz X-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 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