Head gasket?

[DaveGT]

Hi all. I have a 1998 afn engined a4 1.9 tdi. Recently it's started losing water and I can't find a leak. I have to top up the coolant everyday. During my journey the heater doesn't get very warm and after a while will suddenly blow stone cold at which point the engine temp starts to rise above the half way mark where it normally sits on the gauge. It seems dependant on how I drive. Once the heater blows cold if I drive it hard the temp rises. If I back off and take it steady the temp falls back to the half way mark. It's had a brand new thermostat and water pump only a couple of months ago. Is there a special technique for bleeding the coolant system or does this sound more sinister like head gasket failure?
Thanks in advance
Dave

 

[tazzy baby]

on my old b5 there was a bleed screw on the rad to bleed the system it was on the bottom left corner behind the bumper other than that it could be the gasket sorry fella

 

[DaveGT]

No worries. Thanks matey. Just wanted to check before I start pulling the head off

 

[DaveGT]

Once up to temp the coolant hoses are rock hard pressurised as well if this is any help

 

[B5NUT]

sounds like a head gasket failure