Air suspension failure
Discovery air springs, compressors, and valve blocks leak with age on LR3, LR4, and Discovery 5 cars, dropping the truck overnight or triggering suspension warnings. It is the model's signature expensive repair, and many owners sell at the first sag.
Engine cooling and head gasket issues (early V8s)
The early Rover V8s are notorious for cooling system neglect, slipping cylinder liners, and head gasket failure, especially on Discovery Series II cars. A liner or gasket job on an old Discovery exceeds the truck's market value, so owners sell.
Electrical faults and module corrosion
Water leaks into the cabin and tailgate area corrode body control modules on LR3 and LR4 cars, causing door, window, and lighting faults that are hard to trace. Owners faced with module replacement quotes commonly choose a sale over chasing wiring.
Front suspension and drivetrain wear
Heavy Discoverys wear front control arm bushings, ball joints, and front differential components, and transfer case wear produces binding in turns on higher-mile cars. Combined with air suspension needs, the front-end bill often tips owners into selling.
Every one of these is a condition answer on the form — report it and it is priced in from the start, never discovered at pickup.