I post a message earlier regarding the problem with no warm air blowing from the vents in the cabin while at idle. I now don't have any warm air when driving either! There is no evidence of coolant leaks. A few days ago while changing the spark plugs, I remember hearing a clicking sound coming from the area of the heater valve/aux cooling pump with the ignition on. Now, I don't hear that clicking sound! Adnan mentioned I might have a problem with the aux cooling pump. I believe his recommendation is correct. After reading the bentley on this, I might also have a problem with the heater valve. Does anyone know how to check if either the heating valve or aux cooling pump is working properly? Or has anyone else had a similar problem and how did you fix it?