2000 Audi A2 (8Z)

The A2's 75bhp 1.4 16v MPI petrol (AWW/AUA/AXP family) is one of the toughest small engines of its era, but Autocar's used guide singles out the coil pack as its recurring fault. Owners on the A2 Owners' Club forum describe exactly the same chase: a cylinder drops out, a diagnostic reads misfire on one cylinder, and a new Bosch coil pack (plus plugs and often leads) clears it. Failure usually shows first when damp gets into the pack area; a neglected misfire will overheat the catalytic converter, turning a £150 fix into a four-figure one.

Symptoms: Rough idle and shudder under load, often worse in wet weather, Engine management light flashing or steady...

Est. repair cost: £120-£260 for a new coil pack and plugs fitted

The A2 carries its 12V battery in a well under the boot floor. Autocar's used buying guide warns to check for water in the battery compartment caused by tired seals in the rear bumper, and the A2OC's pinned how-to thread identifies the exact culprits: the bumper vents and their flimsy seals, which dislodge after even a light shunt or a bumper replacement, letting water sheet into the bay - members call it the 'fishtank'. Drowned batteries, corroded earth points and tail-light circuit faults follow; the permanent fix is a bumper-off refit with new seals, and repeated partial repairs rarely hold.

Symptoms: Damp carpet or standing water under the boot floor panel, Corroded or replaced battery in the boot well...

Est. repair cost: £120-£450 (new seals and battery/electrical repairs)