Hi There ...... Need Help .... I have Audi 1.9TDi 130 B5 52/2002 - The cooling system and tempguage were fluctuating between normal & zero. Kept topping up with fluid bout 5ltrs! Did a pressure and vacuum test.. no real problems on exhaust or cooling system & did colour test for gasket leaks & no strange coloured oil ..... So changed - waterpump (+cambelt)/ thermostat & sensor/ Radiator/ Pressure cap on expansion tank/ checked aircon/ flushed the system/ further pressure and vacuum test.... STILL getting same problem with the guage running to normal initially then dropping to zero then maybe coming back up & then dropping back & staying at zero... has anyone got any ideas.... PLEASE!