How many miles on the odometer? If it's over 120k then you might be in for a bigger surprise than just a simple leak. Like Subi's the all aluminum Land Rover slug box likes to crap head gaskets like their free. I'd bet a buck that is why the heater core is bypassed and all the other hillbilly fixes. The fan clutch is the number one part that needs replacement every 30k or so, even if it isn't overheating it's good insurance against it and don't skimp on it. It's the most overlooked part of any cooling system and it begins the cascade of all the other cooling failures when overheating begins with these motors. You check the head gaskets by doing a simple compression test with bleed down. If a cylinder is bleeding down fast it's more than likely the head gasket. The other test is run the engine cold for 40 seconds and shut it off. If you get pressure when removing the radiator plug on top then it's a head gasket. Real simple test. If you want to go another route you can run the motor until the thermostat opens with the fill plug off, if you get bubbles making a run for it...... it's a head gasket failure.

 

 

White smoke out the tail pipe is another giveaway (not the good kind like free money). When the motor and coolant is cold try spinning the fan and compare it to when both are hot. Try it hot with the engine off and see if it spins, if it spins easily the fan clutch is shot. It should resist spinning when hot. Irontite is a good cooling system cleaner, have the heater core hooked up if you go that route. 12 minutes and done.

 

 

Yes, just warm it up so the thermostat is open (before it overheats). Irontite Products Inc Home Page