EXTERIOR
Rust is a serious Sierra problem, but by now most three-door Cossies have been restored or in need of very little work. But don’t take it for granted; even a low-mileage or renovated car requires a thorough inspection.
Work your way up from the bottom, checking the floorpan and chassis rails (especially the rear box sections near the spring seats), inner and outer sills, front crossmember and boot floor, particularly around the bumper mounts.
Examine the doors, front wings and tailgate, along with the boot aperture (beneath the rubber seals) and A-pillars, plus the inner and outer wheelarches (where muck gathers behind the plastic extensions and inner liners).
The Sierra’s engine bay is prone to corrosion and stress fractures. Look at the bulkhead, battery tray and inner wings, paying close attention to the suspension turrets, which are known to fold inwards and collapse; another warning sign is excessive negative camber on the front wheels.
Check the headlamps for yellowed lenses, make sure the fog lamps and indicators aren’t cracked, and ensure the grille doesn’t have snapped lugs. Cosworth bumpers can sag, and are becoming increasingly expensive. Likewise, the iconic rear wing, which is prone to snapping on its mounts. It’s common to find loose trim after being removed for restoration, and even simple stuff can be crazy money; look up the cost of side rubbing strips as an example.
If the Sierra is still on its original cross-spoke alloys, check the lacquered diamond-cut finish isn’t flaking, and ensure the centre caps still have their locks.
Accident damage may also be evident (huge numbers of Cossies were crashed), so inspect the hidden areas beneath the boot mat and behind trim. Collectors want to see original/uncut panels (with date stamps on the front wing rails), factory seam sealer and paintwork; all three colours are equal in value.