1998 · 26 years old at test · Petrol mostly

1998 Porsche 911 MOT pass rate and common faults

1,009 MOT tests in 2024. 81.1% passed first time, compared with 64.9% for all cars the same age.

125Well above average
Passed first time81.1%
Failed or needed repairs18.9%
Typical mileage at test95,000

Most common reasons for failing

Share of all 1,009 tests where this item caused a failure.

  1. Catalyst emissions: Lambda reading after 2nd fast idle outside specified limits2.5%
  2. Rigid brake pipes: excessively corroded1.5%
  3. Headlamp: not working on dipped beam1.5%
  4. Wipers: does not clear the windscreen effectively1.4%
  5. Horn: not working1.4%
  6. Washers: not working1.2%
  7. Rbt (sp): efficiency below requirements0.9%
  8. Tread depth below requirements of 1.6mm0.8%
    22 marked dangerous
  9. Suspension arms - ball joint: ball joint excessively worn0.8%
  10. Service brake performance: efficiency below requirements0.8%

Problem areas

Failure items found per 100 tests, by part of the car.

  1. Lights & electrics14.5%
  2. Brakes8.1%
  3. Emissions & leaks4.7%
  4. Suspension4.5%
  5. Visibility (wipers, screen, mirrors)4.1%
  6. Tyres2.0%
  7. Body & chassis1.2%
  8. Seat belts & airbags1.2%

Most common advisories

Not failures yet, but things the tester warned about.

  1. Rigid brake pipes: excessively corroded12.9%
  2. Engine oil leaks: leaking excessively from engine8.6%
  3. Tread depth below requirements of 1.6mm7.6%
  4. Brake discs: in such a condition that it is seriously weakened7.3%
  5. Linkage ball joints: ball joint excessively worn5.1%

What this means if you are buying one

This model year does better than most cars its age, so it is a reasonable used buy on MOT record alone. Before buying, check the area that fails most: catalyst emissions: lambda reading after 2nd fast idle outside specified limits. Then look up the car's own MOT history on GOV.UK with its number plate, and look for repeat advisories.

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Questions

What is the MOT pass rate for a 1998 Porsche 911?

In 2024, 81.1% of 1998 Porsche 911 cars passed their MOT first time, across 1,009 tests. The average for all 26-year-old cars was 64.9%.

What are the most common MOT failures on a 1998 Porsche 911?

The most common failure reasons were catalyst emissions: lambda reading after 2nd fast idle outside specified limits; rigid brake pipes: excessively corroded; headlamp: not working on dipped beam. The biggest problem area was lights & electrics.

Is the 1998 Porsche 911 reliable at MOT time?

Its MOT Rank score is 125, which is well above average for a car of its age (100 means exactly average).