Used car guide

2004 MG ZT diesel: common problems and MOT failures

What MOT testers find on the diesel MG ZT first registered in 2004 (diesel cars only): we looked at the 466 MOTs these cars had during 2023–2025. Plus known faults and what to look at before you buy one.

Small sample: there were only 466 MOTs of these cars during 2023–2025, so treat the percentages as rough. The known faults below don't depend on it.

466MOTs of 2004 diesel cars, done in 2023–2025
56%pass first time (all 2004 cars: 57%)
6,200typical miles a year
3.4×the usual rate for suspension arm

What goes wrong more than usual on a 2004 MG ZT diesel?

Parts flagged at MOT more often on the 2004 MG ZT diesel than on all cars registered in 2004.

  • Suspension arm3.4× usual
    MG ZT
    11.4% All 2004 cars
    3.4%

    Failed outright at MOT: 3.2%, against 0.4% of all 2004 cars. The rest were advisories or minor defects.

    Rough price £120–£180 (one arm) ClickMechanic

    At the viewing: Listen for clunks over bumps and feel for the steering wandering. Worn arm bushes show as cracked rubber near the wheels.

  • Airbag warning light4.9× usual
    MG ZT
    8.4% All 2004 cars
    1.7%

    Failed outright at MOT: 8.4%, against 1.5% of all 2004 cars. The rest were advisories or minor defects.

    Rough price £10–£80 our estimate

    At the viewing: Ask a friend to check every light while you work the switches: indicators, brake lights, fog lights and reversing lights.

Common 2004 MG ZT diesel MOT failures and advisories

The share of 2004 MG ZT diesel MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Suspension
    48% 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.

  • Brakes
    45% 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 electrics
    37% of testsRough price £10–£80

    At the viewing: Ask a friend to check every light, including brake lights and indicators, while you operate them.

  • Tyres
    30% 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.

  • Rust and bodywork
    11% 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.

  • Wipers, windscreen and mirrors
    10% of testsRough price £15–£250

    At the viewing: Check for chips in the driver's view, and test the wipers and washers.

Questions to ask the seller before buying a 2004 MG ZT diesel

Ask before you travel to see it. A seller who knows the car will have answers, and receipts.

  1. Any recent work on the suspension arm? (Flagged at MOT 3.4× as often on the 2004 MG ZT diesel as on other cars the same age.)
  2. Any recent work on the airbag warning light? (Flagged at MOT 4.9× as often on the 2004 MG ZT diesel as on other cars the same age.)
  3. Can I see the service history and receipts for any big jobs?

Looking at an MG ZT?

Check the actual car: its own MOT history, mileage and what to ask the seller. Free, no sign-up.

Other years

Every year of the MG ZT compared

YearMOT testsMost flagged
2007–Too few tests
2006259Suspension 38%
2005913Suspension 44%
2003908Suspension 42%
2002476Suspension 43%
2001203Suspension 45%

Where this comes from: the DVSA's anonymised results for every MOT test done in Great Britain during 2023–2025, counting the MOTs of MG ZT cars first registered in 2004. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score