Hey guys, 2001 Disco II with 86k miles is overheating. Changed the Waterpump, a few hoses and the thermostat about 6 months ago. No problems for a while. Recently got some swishing noise from the heater core. Now, it'll heat up to normal op temp, but the heat's still blowing cold, then will overheat and the reservoir is extremely hot. Got some pressure noises coming from the thermostat and heater core areas too. Looked around on the forums a little and found some similar questions but not really an answer.....thanks.
JE

 

check for leaks. it goes low cause of the leaks.

 

how many miles on your truck? when was the last time you changed the thermostat? you need to bleed your system and add coolant.