Free tool · no signup
Common Faults Checker
Enter a registration to see what actually fails on that model at that age — brakes, suspension, tyres, corrosion, emissions — measured from millions of real MOT results, and whether this car already has a record of it.
Free · no signup · from DVSA's published MOT results
How the common faults checker works
We identify the car
DVLA's vehicle record gives the make, model, fuel and date of first registration — so we know exactly which cars to compare it against.
We compare like with like
Against every car of the same model, age and fuel in DVSA's published MOT results. Never against 'all cars' — an older model would look bad simply for being older.
We check this car's own record
Its MOT failures and advisories are sorted into the same categories, so you can see where the model's weak spot and this car's history line up.
What this is, and what it isn't
It is measured, not curated. There is no list of “known engine faults” behind this. No manufacturer publishes that their engine fails, so any such list would be hearsay presented as fact. What you see here is what MOT testers actually recorded, on millions of tests.
It describes the model, not your car. A high rate means the category is worth checking on this model. It is not a prediction, and it is not a diagnosis.
It reflects use as well as design. High mileage, short journeys and deferred servicing all show up as failures. A well-kept example of a “bad” model can be in better condition than a neglected good one — which is exactly what a service history check tells you.
Common questions
Where do these failure rates come from?
DVSA publish every anonymised MOT test result and failure item as open data. We aggregate two years of it into failure rates by defect category for each model, age and fuel, and compare each model against every car of the same age and fuel. The data is public sector information licensed under the Open Government Licence v3.0; the categories, cohorts and comparisons are ours.
Does a high failure rate mean my car has a problem?
No. It describes other cars of the same model, age and fuel — not this one. It tells you which categories are worth checking on this model, and the tool separately shows whether this particular car already has failures or advisories in those categories.
Why does it say nothing for my car?
A cohort needs at least a thousand first MOT tests before we publish a rate for it. Below that the figure could be wrong by half, so we publish nothing rather than a number that looks precise and is not. Cars under three years old have not had a first MOT at all.
Why are some comparisons shown without a multiple?
Every ratio is taken from the conservative end of its confidence interval. Where a model is only slightly above average, the data cannot tell the difference from noise, so both rates are shown and no multiple is given.
Does this include advisories as well as failures?
The model-level rates count failures only — the categories that actually failed a test. For the specific car, both its failures and its advisories are shown, because an advisory is an early warning of the same thing.
Is this the same as a service history check?
No. This is free MOT data. A service history check returns the manufacturer's own dealership service records for a specific vehicle — what work was done, when, at what mileage and by which dealer. That is the paid report.