2012 MINI Coupe (R58)

The turbocharged Coupe - 184hp Cooper S (N18B16) and the 211-218hp JCW - runs the chain-driven Prince engine that stretches when oil runs low or overheats on extended 2-year/16,000-mile service intervals. PistonHeads is blunt: the cam chain lasts the life of the 122hp Cooper but wears on the turbo S and JCW, and prices the full chain replacement at around £850 at an independent specialist; MINI specialist Lohen sells its N18 death-rattle chain fix at £820 fitted, blaming the tensioner losing efficiency and sometimes failing outright. Left ignored, the chain skips teeth and destroys valves, turning an £850 job into a scrap-the-engine event.

Symptoms: Diesel-like rattle for several seconds from cold start, Rattle persisting or worsening after oil level is corrected...

Est. repair cost: £750-£950 for specialist chain, guides and tensioner work

Not dangerous but constant: PistonHeads reports the Coupe's parcel shelf, which covers the deep tailgate-access boot, can be rattly over rough surfaces, and that keyless fob actuation of the rear lid did not always work for every owner, while Auto Express expects squeaks and creaks from the firm suspension and trim on high-mileage cars. On the UK pothole network this is the most commonly experienced nuisance on the body style, and at a viewing it doubles as a useful probe - a rattling shelf often means lost clips or a loose boot lining hiding damp, and a dead fob release points at tailgate switch or module corrosion.

Symptoms: Rattle from the parcel shelf area over bumps, Key fob failing to release the rear tailgate intermittently...

Est. repair cost: £0-£300 for clips, lining refits and release switch/motor diagnostics