Mercedes-Benz Sl400 common MOT failures and failure rate
What a Mercedes-Benz Sl400 fails its MOT on, from real DVSA test data, and the part that resolves each item.
Based on 109 MOT tests in DVSA data.
About 3.7% of MOT tests recorded on the Mercedes-Benz Sl400 in DVSA data end in a failure. The same handful of items account for most of them.
Its most common failure is suspension, which makes up 50.0% of the Mercedes-Benz Sl400's failures, followed by suspension, registration plate, tyres. Each item below links to the part that resolves it. Confirm the exact fitment against your registration or VIN before buying, and have safety-critical work done by a competent mechanic.
What it fails on, and why
Suspension failures usually mean a worn or snapped coil spring, a leaking shock absorber, or play in a lower arm ball joint or bush. The tester checks for corrosion, fractures and excessive movement. A broken front spring is one of the most common failures on higher-mileage cars and is a straightforward replacement.
A missing, damaged, dirty or incorrectly-spaced number plate, or one using the wrong font, will fail. A replacement plate is inexpensive.
Tyres fail for tread below the 1.6mm legal limit across the central three-quarters, uneven or exposed-cord wear, or sidewall damage. The tester inspects all four; a single illegal tyre is a fail.
The parts that fix each
If your car has just failed, you have 10 working days to fix the items and get a free partial retest. These are the usual parts; confirm the exact fitment against your registration or VIN before buying.
Other models
Sources: DVSA MOT History API: MOT test results and defect data ยท DVSA MOT testing data for Great Britain