Range Rover Classic cooling system is a standard water-cooled
This is of lead-soldered brass construction, with the
tubes running horizontally between two tanks (hot on the left,
cold on the right side of the vehicle).
The movement of the engine under load (in the opposite direction
to rotation of the crankshaft) applies a twisting motion to the
radiator via the hoses causing it to "lozenge", which
in turn can often lead to failure of the lead-soldered joints.
My radiator has required one repair and one re-build for this
Beware, there are different radiators for vehicles
with and without air conditioning.
This is a standard "waxstat" type, mounted in the inlet
manifold waterway, under the fitting to which the radiator top
hose is attached. The thermostat can fail, as mine did. In the
picture you can see the scuff marks on the copper part, where
it was sticking
When tested, by boiling it up
in a saucepan of water, it began to open at the correct temperature
of 88 deg C, but because of the sticking it didn't open
fully until 100 deg C. This proved to be the cause of
the engine running hot, with the temperature gauge needle well
into the top half of the scale. It was cured by replacing the
thermostat, after which the temperature gauge needle was in the
(you can also see that the white
plastic jiggle-pin has turned green after 21 years immersion
in Unipart antifreeze, which contains fluorescein!)
Loss of coolant
This may be a symptom of head gasket failure.
Other causes may include:-
The Rover V8 engine, particularly in it's larger
capacity variants as used in the P38A, is prone to cracking of
the block and loosening of the cylinder lining. It has been suggested
that this is due to the fuel mapping, designed for economy and
emissions, giving too weak a mixture at low revs with full throttle,
leading to overheating.