1 CHECK FOR RUST
Corrosion is the biggest Discovery killer. The chassis fares better than the body, but check around body mounts. The body’s weak points are the front and rear wheelarches and the sills. Check behind the plastic sill cover and wheelarch linings if you can, and have a look at the boot floor.
2 HOW STANDARD is IT?
Extreme suspension lifts and huge tyres look the business and help off-road, but can ruin onroad road performance. Subtler interferences might include bodged immobiliser repairs, poorly executed welding, or illadvised tweaks to the fuel pump (look for excessive black exhaust smoke under load).
3 DRIVETRAIN ISSUES
Breakages are rare but worn axle differentials are common, and replacements are expensive. Listen for whining on the motorway or clonks when taking up drive. Also, with the handbrake off, turn the propshafts by hand to isolate play in the diffs or universal joints. Check the front swivels; corrosion and leaks here spell imminent MoT failure.
4 INTERIOR & ELECTRICS
Trim is generally hard-wearing, though the dash is a bit brittle. Sunroof leaks are common, even with new seals fitted, which can warp the trim, accelerate internal corrosion and create issues with the immobiliser; fixes are cheap, but often time-consuming.