Series Land Rover Overheating Problems - Part 1
The original Series Land Rover radiator is of a 4-core design and is well able to cope with tropical climates and working machinery via a PTO whilst the vehicle is stationary. Therefore, overheating problems are most likely to be the result of a coolant circulation problem. The original 4-core radiator has a flat top and is now difficult to source and 3-core models (curved top), offered in replacement, are not up to the same capability. If a structural fault is found with the 4-core radiator it would be best to get the radiator repaired or rebuilt, if possible, rather than substitute a 3-core version.
If overheating is a problem then the following checklist is useful in discovering the cause:
*Check coolant level in the radiator is sufficient (allow time to cool before removing radiator cap).
*Check for water movement in the top of the radiator when the engine is running. No movement suggests a stuck thermostat or collapsed radiator hose.
*Check for obstructions such as insects etc in the radiator cooling fins.
*Is there sufficient engine oil?
*Is the fan belt slipping?
*Is there compression at the exhaust tailpipe, indicating there is no obstruction in the silencer or pipes.
*Are the wheel rims hot after a short journey - binding brakes can cause the engine to overwork.
*Did you create an air lock in the system when draining and refilling the system recently?
*Was the engine rebuilt recently and poorly re-assembled - causing bearings to bind.
*Is the valve timing correct?
*Is the ingintion timing
too far retarded?
*If you have an aftermarket temperature gauge fitted it needs to be connected to the voltage stabiliser to receive 10volt NOT 12volt else it will read high.
Other causes of overheating can be:
for petrol engines - the fuel mixture could be too weak.
for diesel engines - the injectors could be faulty or fuel distributor pump settings could be at fault; in either case, professional diesel engine assistance is desirable.
If hilly terrain is causing overheating, then easing your foot off the accelerator on downhills, whenever practical, will cause engine cooling, as less heat-generating fuel will be burnt.
Old engine blocks often have corrosion sediment in the water jacket which could be flushed out. To do this, disconnect both radiator hoses from the engine, remove the thermostat housing and the thermostat and then refit the the housing. Wind strips of cloth around the end of a garden hose and push it into the lower engine coolant inlet. Backflush the system then refit the thermostat. You will require a new thermostat housing gasket or gasket compound (brown paper greased on both sides is a temporary substitute). A similar method can be used to backflush the radiator.
In an emergency, to assist engine cooling, switch on the heater.
The 2.6litre engine has an aluminium cylinder head that is more easily damaged if overheated.
Overheating problems Part 2 (opens in a new window) focusses upon the specific situations of either steam issuing from under the bonnet, or a definate smell of overheating.
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