Hi I have an A4 TDI B5 chassis, i can't get the bottom hose warm? please can someone tell me how or what to look for. I have just put a 38,000 mile engine in, I have refilled the coolant twice now took the brand new thermostat out and tested all ok there was water both sides of the thermostat, filled it up like it says in the haynes book engine runs sweet needle stays at 90 top hose nice and warm rad still cold. The viscous fan is always spinning should it? also do you think it maybe the water pump? please help driving me mad now.