2021 Ford S-Max diesel: common problems and MOT failures

What goes wrong more than usual on a 2021 Ford S-Max diesel?

Parts flagged at MOT more often on the 2021 Ford S-Max diesel than on all cars registered in 2021.

• Brake pads2.7× usual
  Ford S-Max

  16.1% All 2021 cars

  6%

  Failed outright at MOT: 3.5%, against 1.1% of all 2021 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.

• Headlights8.5× usual
  Ford S-Max

  3.4% All 2021 cars

  0.4%

  Failed outright at MOT: 3.3%, against 0.4% of all 2021 cars. The rest were advisories or minor defects.

  Rough price £40–£400 our estimate

  At the viewing: Check both headlights on dipped and full beam, and look for cloudy or cracked lenses.

• Number plates4.7× usual
  Ford S-Max

  3.8% All 2021 cars

  0.8%

  Failed outright at MOT: 0.6%, against 0.2% of all 2021 cars. The rest were advisories or minor defects.

  Rough price £5–£40 our estimate

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

• Engine warning light5.5× usual
  Ford S-Max

  2.2% All 2021 cars

  0.4%

  Failed outright at MOT: 2.2%, against 0.4% of all 2021 cars. The rest were advisories or minor defects.

  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.

Common 2021 Ford S-Max diesel MOT failures and advisories

The share of 2021 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
  28% 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
  20% 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
  10% 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
  5% of testsRough price £80–£250

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

• Wipers, windscreen and mirrors
  4% of testsRough price £15–£250

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

• Suspension
  1% of testsRough price £120–£400

  At the viewing: Listen for knocks over speed bumps, and look behind each front wheel for a snapped coil spring.

Known faults on the 2021 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 2021 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 brake pads? (Flagged at MOT 2.7× as often on the 2021 Ford S-Max diesel as on other cars the same age.)
3. Any recent work on the headlights? (Flagged at MOT 8.5× as often on the 2021 Ford S-Max diesel as on other cars the same age.)
4. Any recent work on the number plates? (Flagged at MOT 4.7× as often on the 2021 Ford S-Max diesel as on other cars the same age.)
5. Can I see the service history and receipts for any big jobs?