Symptoms
An ageing cooling system on a 4.0 or 4.6. Cracked or soft hoses, a high or overfilling expansion tank, or a heater that blows lukewarm. On these engines, overheating is what leads to slipped liners and blown head gaskets.
The fix, step by step
- Remove the reservoir cap and drain the system from the radiator's bottom plug with a 12 mm Allen socket.
- Expect roughly 11–12 litres (about 3 US gallons).
- The thermostat is an external 'artificial heart' unit held by its hoses next to the radiator.
- Replace it with the lower hose from underneath, then do the top hose, heater hoses and bypass hoses.
- While the hoses are off, unbolt and check the metal down-tube for rust blockage.
- There is no bleed screw.
- Fill, warm the engine fully, let it cool completely, then top up again.
- Run the heater to confirm the core isn't air-locked.
Tools & part numbers
- 12 mm Allen socket on a ½-in drive
- hose-clamp pliers
- 5-gallon drain pan
- Atlantic British kit 9369SKA (1995–99 GEMS trucks)
Where to buy the parts
P38 coolant hose & thermostat kitAtlantic British ↗Amazon ↗
Hunting a used or discontinued part? Search eBay Motors for Land Rover Range Rover P38A parts →
Rated for a competent home mechanic with a decent tool kit. Confirm torque figures, fluids and procedures against the factory service manual for your VIN, support the truck on stands rather than a jack, and work at your own risk (disclaimer). Some parts links are affiliate links, which pay us a small commission at no cost to you.