I have an Audi A4 1997 1.9 Tdi (110). The car is suffering from sever coolant loss. I have noticed then when the car is cold and stationary it doesnt really leak much, if atall.

I can fill the coolant expansion tank right up and little, or none will be lost. But then If I take it for a drive, say to the local supermarket, I will come back from getting my bits and there will be a HUGE puddle of coolant under the audi.

I don't have a clue about audi's. But I put it up on some ramps and it is so hard to tell where it is coming from. Because it only leaks when you take it for a drive. I suspect the water pump but I could be completely wrong?

Is this an expensive repair and is there anything I can do to fix it temporarily as I have to use the car over the weekend? I have tried radweld.