Hey guys, just spent a packet on my 1997 t4 1.9td transporter after first the water pump failed then the head gasket did the same.. ouch! Got both replaced now plus timing belt for good measure. The day after I got it back the temperature light came on and I took it back to be told it was a 'settling down' issue, they topped up coolant levels and its been fine for a week. Now, although it seems to be running fine (temp where it should be and no temp light blinking at me), I hear a low hum from under the bonnet after I turn off the ignition, even after a short journey, which I'm assuming is a fan and this continues for anything up to 5 mins then stops. Checked coolant level myself this evening - about half a centimetre over minimum. Anything to worry about?