1994 Rover Metro 1.1L Petrol · M456 KOE

The Rover Metro replaced the Austin Metro's harsh, separate suspension units with interconnected front-to-rear Alex Moulton Hydragas displacers and interconnected fluid pipes. Over time, the internal nitrogen gas charge in the displacer spheres gradually permeates through the rubber diaphragm, and external steel connection pipes rot in British winter salt. This causes the car to sag onto its bump stops, ruining the ride quality and destroying front tyre alignment. Regassing displacers requires specialist equipment and rare replacement units.

The Rover Metro debuted Rover's all-aluminium K-Series engine (1.1 8v, 1.4 8v, and 1.4 16v GTi). Early K-Series engines utilised plastic locating dowels between the cylinder block and head, a small 3.5-litre cooling capacity, and an elastomer-bead cylinder head gasket. Thermal expansion differentials and minor coolant loss quickly cause the head gasket to blow, warping the lightweight aluminium cylinder head and contaminating the engine oil with coolant.

While the Rover Metro received galvanised zinc coating on certain vulnerable lower panels compared to the Austin original, British road salt takes a heavy toll on the A-pillars, lower sills, jacking points, and rear wheel arch returns. Water also penetrates behind the front wing seals and drains into the A-pillar box section, rotting the door hinge mountings and lower windscreen corners. Structural rust in these zones is a primary cause of MOT failure.