MOT cost .

Ford

Sierra

2,687 MOT tests analysed. sits above the UK fleet average — here's where Sierras pass, fail, and end up on the retest sheet.

That's 9.0 points above the UK fleet average across our 1,988 tracked models — a confident result.

Pass

84.7%

Pass-after-fix

3.0%

Fail

11.3%

Avg miles

52,262

Pass + Pass-after-fix + Fail = 100%

The picture

Sierra: above-average pass rates, with caveats

Across 2,687 MOT tests, the Sierra returns 84.7% first-time pass — above the UK fleet average. The single most-logged Major fail is a split CV-joint boot. The strength or continuity of the load bearing and windscreen damage round out the top three. Average tested mileage sits at 52,262, which is the lens to read those failure rankings through. If you own one and the next test is close, the ranked list below is a sensible pre-test checklist.

Top ten reasons for rejection.

  1. 01

    A transmission shaft constant velocity joint boot severely deteriorated

    70 occurrences · 2.6% of tests

  2. 02

    The strength or continuity of the load bearing structure within 30cm of any sub-frame, spring or suspension component mounting (a 'prescribed area') is significantly reduced or inadequately repaired

    67 occurrences · 2.5% of tests

  3. 03

    Windscreen or window damaged or seriously discoloured but not adversely affecting driver's view

    58 occurrences · 2.2% of tests

  4. 04

    Emissions levels exceed default limits

    49 occurrences · 1.8% of tests

  5. 05

    Vehicle structure corroded to the extent that the rigidity of the assembly is seriously reduced

    37 occurrences · 1.4% of tests

  6. 06

    A transmission shaft constant velocity joint boot missing or no longer prevents the ingress of dirt etc

    34 occurrences · 1.3% of tests

  7. 07

    Exhaust system leaking or insecure

    30 occurrences · 1.1% of tests

  8. 08

    Wiper blade defective

    28 occurrences · 1.0% of tests

  9. 09

    The strength or continuity of the load bearing structure within 30cm of any seat belt anchorage (a 'prescribed area') is significantly reduced or inadequately repaired

    28 occurrences · 1.0% of tests

  10. 10

    Wiper blade missing or obviously not clearing the windscreen

    27 occurrences · 1.0% of tests

Counts cover Major and Dangerous defects logged at test. Advisory items excluded so this shows why a car was rejected, not just what the tester flagged in passing.

Try the calculator

Build your own retest budget.

Buying or keeping a Sierra?

Use the failure ranking as a pre-test checklist or a haggling lever. Treat the headline pass rate as a fleet-wide trend, not a guarantee on any individual car.

If you own a Sierra and your last MOT looked nothing like the ranked failures above, that's normal — individual cars vary widely. The ranking shows the patterns testers flag most often across the country.