Used car guide

2018 Ford S-Max diesel: common problems and MOT failures

What MOT testers find on the diesel Ford S-Max first registered in 2018 (diesel cars only): we looked at the 6,208 MOTs these cars had during 2023–2025. Plus known faults and what to look at before you buy one.

6,208MOTs of 2018 diesel cars, done in 2023–2025
80%pass first time (all 2018 cars: 83%)
8,400typical miles a year
1.6×the usual rate for tread depth

What goes wrong more than usual on a 2018 Ford S-Max diesel?

Parts flagged at MOT more often on the 2018 Ford S-Max diesel than on all cars registered in 2018.

  • Tread depth1.6× usual
    Ford S-Max
    27.1% All 2018 cars
    17.1%

    Failed outright at MOT: 3.1%, against 2% of all 2018 cars. The rest were advisories or minor defects.

    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.

  • Brake pads1.8× usual
    Ford S-Max
    20% All 2018 cars
    10.9%

    Failed outright at MOT: 3.9%, against 2% of all 2018 cars. The rest were advisories or minor defects.

    Rough price £75–£175 (one axle) ClickMechanic

    At the viewing: Listen for squealing or grinding when braking, and look through the wheel at how much pad is left.

  • Wipers1.8× usual
    Ford S-Max
    5.1% All 2018 cars
    2.8%

    Failed outright at MOT: 3.4%, against 1.8% of all 2018 cars. The rest were advisories or minor defects.

    Rough price £15–£60 our estimate

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

  • Engine oil leaks3.2× usual
    Ford S-Max
    3.2% All 2018 cars
    1%

    Failed outright at MOT: 0.1%, against 0% of all 2018 cars. The rest were advisories or minor defects.

    Rough price £80–£600 our estimate

    At the viewing: Look under the engine and where the car is usually parked for fresh oil. Ask whether the leak has been looked at.

Common 2018 Ford S-Max diesel MOT failures and advisories

The share of 2018 Ford S-Max diesel MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Tyres
    34% of testsRough price £70–£150

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

  • Brakes
    25% of testsRough price £150–£350

    At the viewing: Look for a lip on the disc edges and feel for judder or pulling when braking firmly from about 40mph.

  • Lights and electrics
    9% of testsRough price £10–£80

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

  • Seats and seatbelts
    9% of testsRough price £80–£250

    At the viewing: Pull each seatbelt sharply. It should lock, and retract cleanly.

  • Wipers, windscreen and mirrors
    8% of testsRough price £15–£250

    At the viewing: Check for chips in the driver's view, and test the wipers and washers.

  • Oil and fluid leaks
    3% of testsRough price £80–£600

    At the viewing: Look under the engine and on the ground where the car is usually parked for fresh oil or fluid.

Known faults on the 2018 Ford S-Max diesel

Reported by owners, mechanics and buying guides for this model and age. Check which engine the car has, as some apply to one engine only.

  • Oil pump belt that runs in oil (2.0 EcoBlue diesel)

    2.0 EcoBlue diesel (most Ford 2.0 diesels from about 2018)

    The 2.0 EcoBlue diesel drives its oil pump with a belt that runs in the engine oil. As it wears it can shed rubber and cut oil pressure, which can wreck the engine. Ford has shortened the change interval on the Transit to 6 years or 100,000 miles.

    At the viewing: Ask when the oil pump belt was last changed, and watch for an oil-pressure warning light.

    Source: Parkers: everything you need to know about the Ford wet belt

Questions to ask the seller before buying a 2018 Ford S-Max diesel

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

  1. Has the oil pump belt been changed, and is there a full service history?
  2. Any recent work on the tread depth? (Flagged at MOT 1.6× as often on the 2018 Ford S-Max diesel as on other cars the same age.)
  3. Any recent work on the brake pads? (Flagged at MOT 1.8× as often on the 2018 Ford S-Max diesel as on other cars the same age.)
  4. Any recent work on the wipers? (Flagged at MOT 1.8× as often on the 2018 Ford S-Max diesel as on other cars the same age.)
  5. Can I see the service history and receipts for any big jobs?

Looking at a Ford S-Max?

Check the actual car: its own MOT history, mileage and what to ask the seller. Free, no sign-up.

Other years

Every year of the Ford S-Max compared

YearMOT testsMost flagged
2026–Too new for MOT data
2024–Too new for MOT data
2023–Too new for MOT data
2022796Tyres 26%
20211,500Tyres 29%
20203,445Tyres 29%
20196,889Tyres 32%
201715,741Tyres 35%
201620,447Tyres 36%
20159,826Tyres 38%
201419,428Tyres 41%
201318,553Tyres 41%
201220,783Suspension 43%
201119,110Suspension 45%
201026,056Suspension 48%
200917,396Suspension 53%
200813,456Suspension 59%
200713,655Suspension 61%
20064,441Suspension 62%

Where this comes from: the DVSA's anonymised results for every MOT test done in Great Britain during 2023–2025, counting the MOTs of Ford S-Max cars first registered in 2018. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score