2001 Land Rover Range Rover 4.0L Petrol · SD51 EFH

Autocar's P38 guide lists air suspension problems that 'often go unresolved': leaks make the pump work overtime, the pump fails, is replaced and fails again, so the system must be proved leak-free. Hagerty puts the sequence plainly - the compressor usually dies trying to keep leaking airbags inflated, so replacing it is simple but is not a cure - and recommends spraying the bellows with soapy water and cycling all five heights. LandyZone owners add the valve block: diaphragm failure inside it, not stuck solenoids, is the usual cause of a 'valve stuck' fault code, and the solenoids should never be lubricated.

Autocar singles out the 4.6 as 'known for dodgy cylinder liners and springing internal coolant leaks', with the steel liners corroding the aluminium block and letting coolant into the combustion chamber where it vapourises - usually from about 90,000 miles onwards and an expensive fix, though the 4.0 is less prone. Hagerty describes the same family from the mechanical side: liners that slip and pressurise the cooling system, a cracked block that then overheats and damages a head gasket, and a blocked top radiator hose finishing the job. A reconditioned block is often the quicker, cheaper route than re-lining.

On the P38 almost every electrical function runs through the body control module under the driver's seat. Autocar's workshop quote is unambiguous: water ingress can damage it 'but it doesn't need an excuse - one day it'll be fine and the next it'll be up the creek', and a full service history is no protection. Hagerty tells buyers to peer under the seats for water marks on the ECU control units, which usually means the car has been driven through deep water, and warns that a weak battery generates a cascade of error codes and warning lights that look far worse than the fault. Roof drain blockages and leaking door seals are the usual route in.