Disco overheats. then Gauge drops and heater blows hot

Hi my Disco runs very well, but suffers from overheating. I have replaced the head gasket, and the "p" gasket. The symptoms are this; Vehicle seems fine, then one of two things happen. Either, the tempreture will continue to rise well into the "red". If I then stop I find that the top hose area is very hot, although the heater pipes are cool. Or, the tempreture rises, then falls back quickly and the heater blows hot and everything is ok. I have changed the thermostat (Genuine LR) and the headgasket was replaced about 9 months ago, but that gave different symptoms...Any ideas??

you have air in the system Bleed all the air out of the rad etc..

have you checked rad is hot all over when vehicle up to temp,cool heater pipes means your getting air or gasses in system and have lost coolant or was low to start with

air in the system

Thank you for your comments everyone. I will check the Rad, and have a go at bleeding it. Is there a recomended proceedure to bleed?

keep filling till it over flows fron rad bung themostat housing bung and tank ,tank will find its own level after a run

Thanks...

salochinnotlib said:

Thanks...

Click to expand...

There are two bleeding bungs: 1 in the top of the rad and one in the top of thermostat housing.

If you fill up the rad first, then with the header tank cap in place, fill up the thermostat housing and replace the bung.

Now check the level in the header tank, it should be equal to the middle seam on the tank, so about half full.

Keep an eye on it for a few days until it stabilises.