2004 Mazda B Series: common problems and what to check
What gets flagged at MOT on 2004 Mazda B Seriess, from 144 tests in 2025, plus known faults and what to look at before you buy one.
Small sample: only 144 of these were MOT tested in 2025, so treat the percentages as rough. The known faults below don't depend on it.
What stands out
Parts flagged at MOT more often on 2004 Mazda B Seriess than on all cars registered in 2004.
- Chassis rust or damage5.7× usualMazda B Series22.9% All 2004 cars4%
Failed outright at MOT: 4.2%, against 1.2% of all 2004 cars. The rest were advisories or minor defects.
Rough price £150–£1,000 our estimateAt the viewing: Check the sills, wheel arches and underneath for rust, and look along the panels for uneven gaps or paint.
By area
The share of 2004 Mazda B Series MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.
- Brakes41% 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 electrics40% of testsRough price £10–£80
At the viewing: Ask a friend to check every light, including brake lights and indicators, while you operate them.
- Suspension38% 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.
- Rust and bodywork30% of testsRough price £150–£1,000
At the viewing: Check the sills, wheel arches and underneath for rust, and look along the panels for uneven gaps or paint.
- Tyres28% 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.
- Exhaust and emissions15% of testsRough price £100–£1,200
At the viewing: Look for black soot in the tailpipe, listen for blowing from the exhaust and check for engine or DPF warning lights.
Looking at a Mazda B Series?
Check the actual car: its own MOT history, mileage and what to ask the seller. Free, no sign-up.
Other years
| Year | MOT tests | Most flagged |
|---|---|---|
| 2006 | 119 | Lights and electrics 44% |
| 2005 | 307 | Lights and electrics 42% |
| 2003 | 225 | Brakes 45% |
| 2002 | 204 | Brakes 42% |
| 2001 | 105 | Brakes 47% |
| 2000 | 144 | Lights and electrics 42% |
Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 2004 Mazda B Seriess registered in 2004. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score