Club 80-90 Forums

I am aware that this is not a VW problem, however it is an engine problem, and there seem's to be some experienced people on here:
My brother has a Defender 90, with a TD5 engine, which keeps blowing water out of the expansion tank, he has replaced the cap, which made thing's better, around town there is no problem, but on a run of say, 50 mile's on the motorway, it blew 1.5 litres of water out of the tank again. The top pipe from the radiator was cold, and also the pipe to the expansion tank, he has been told this is a head gasket issue, but he has no loss of power, and no white smoke from the exhaust.
The reason he doesn't want to go for a straight head gasket replacement is, that on the TD5 engine he has been quoted between £750.00 and £900.00.
Has anyone any clues ?

probably a stuck or sticky thermostat as the only way to vent the pressure would be back up through the header.
is he loosing water? or steamy exhaust if not then wont be h/gasket as L/R diesels hate water in the pots.
has he bled the system could be a small amount of air in there.
regards doug
t25's lr 90 and all things classic

Ooo never thought of that, the only water he is losing is out of the header tank, it sprays it over the underside of the bonnet, no steam or anything from the exhaust at all.

When filling up top up the radiator and fill the top of the thermostat housing give pipes a big squeeze until you see fluid movement in the header take run up with the header cap removed and feel round the thermostat housing yo make sure that all pipes are warm. Replace cap take for run with your heater on full then top up as necessary

Thank you for your reply's, I have told my brother and tomorrow he will replace the thermostsat and try out the filling of the radiator, wiil let you know of the outcome, just trying to save him some grief.

R kid changed the thermostat today (quite a big job apparantly) and it seem's to have cured the problem, took it for a 30 mile trip and no problems at all.
Thank you to those who gave good advice.