Used MINI One D R50 review and buying guide (2003 to 2007): which one to buy and what to check

Which used MINI One D R50 should you buy?

The MINI One D R50 to buy is the one with quiet power steering and paperwork for any pump or column work, because steering's where the faults keep turning up on this car. The electric motor that drives the steering pump can pack up and overheat its wiring, and steering columns have failed too. A car that's already had the pump or column put right, with the receipt to show it, is a safer bet than one that hasn't.

Don't buy one expecting a frugal diesel, because it's a heavy car and doesn't match its official economy. Check the back of the car before you fall for it: exhaust fumes have marked the paint on light coloured ones, and a rear silencer that's rotting from the inside sheds rust that shows up most on white and yellow cars. That's worth knowing before you settle on a pale colour.

Which MINI One D R50 engine and gearbox are the safe choices?

The One D R50's diesel has one quirk to know about: it can go flat below 1,500rpm in third, with next to no power or torque, so change down rather than labouring it from low revs. One owner of a 2005 car paid £1,577 for a new injection pump, diagnostics included. That's a single car's bill rather than a pattern, but it's still worth asking whether the pump's been replaced and getting the receipt if it has.

Give the gearbox a proper test, because failures after 3 to 5 years have been reported. Listen for noise from it on the drive and feel how cleanly it changes through every gear, up and down. Don't buy one that's noisy or baulks between gears, and ask whether the gearbox has ever been rebuilt or replaced, with the receipt if it has.

What should you check when viewing a used MINI One D R50?

Turn the steering from lock to lock with the engine running and listen hard, because noise from the column means its upper bearing's failed. The electric motor that runs the power steering pump can pack up too, and it's been known to overheat and damage its wiring loom. If the car pulls to the nearside, check whether the front suspension turrets have been pushed up, which needs new top mounts and the turret repaired on a jig.

Watch the dash as the engine starts, because the ABS and ASC warning lights have to go out and stay out; those modules have been known to fail from 3 to 4 years old. Press the brake pedal and pull the handbrake, and if either travels further than it should, a rear calliper's failed. Run the air conditioning for a few minutes too, since an airlock in the refrigerant can make it gurgle and it's hard to clear.

Get underneath and look at the straps holding the fuel tank, which can rust through on MINIs of 7 to 8 years old. Check the rear silencer for rot and the paint around the back for exhaust staining, especially on a light colour. Ask for receipts for any power steering pump, steering column, gearbox or injection pump work, so you know what's already been put right.

Paste the advert into the free check and it runs these against the listing, the MOT history and the DVLA record before you travel.