disco td5 over heating

my td5 discovery has cooling issues and problems with heater firstly the heater only blows hot when i am moving tried bleeding it yesterday raised header tank and got all bubbles out or so i thought but today whilst towing heavey trailer temp guage went into red before red light came on the guage then dropped off, i pulled over opened bonnet and undone bleed screw as header tank was still full had lots of air and top hose was swollen i released the pressure until coolant came out again turned off engine and restarted it guage showed normal again and i managed to get home again i think its prob head gasket (car fitted with a kenlowe fan)

So what is yr qs ?

its a 2004 euro 3

Sounds like head gasket to me too. Have you tried getting a sniff test done? They don't always work on diesels but it may be worth a shot.

bit the bullet and i have booked it in to have the block tested on wednesday but deep down i think its leaking so gonna be an expensive