is it ok to run 1.9 tdi (alh) 01 , without thermostat for the weekend , ill get new thermo on monday , also is water ok instead of coolant for same time (200 miles )

do you mean the electric fan switch has gone or the thermostat that controls the water flow?

If it's the electric one, then you may wish to consider shorting the connection to the switch (i.e. switch removed, shorting the appropriate connections so the fan remains on) if you are likely to get stuck in traffic a lot.

That said it's a derv so it wont run that hot anyway. Water instead of coolant will be fine at the moment, it's not great but it will do, mine was running on that for a lot more than that. Keep an eye on the temperatures though, if it gets near freezing I wouldnt risk it. If it gets a tad hot you can probably help sufficiently at the moment by just turning up the heat inside the car and sticking the fan on a highish speed with the windows down to stay at reasonable temp yourself.

thanks ww vrs, its the thermo that controls the water flow temp that i've taken out, that it was not opening and therefore overheating.thanks for the reply

I'd say as long as the hole is not leaking you should be ok for a while, would not run it for longer than strictly needed though if you can avoid it.

ye i agree , about 200 miles tops , no leaks cos i took rubber seal off thermo itself , now running at 65 - 70 degrees so all sould be fine (i hope) thanks ww vrs