Q: I own a 2004 Land rover Discovery SE7 the heat works when \i drive it however when it is \idle the air blows cold I noticed my coo

Hello. Thank you for writing in. The heating system depends heavily on the function of the cooling system. What is likely happening is a lack of coolant circulation when the car is idling. This is causing the coolant to sit stagnant and the heater has no supply of hot coolant coming into the heater core in order to heat the air coming in. It may be due to the water pump, which is tied into the drive belts. When the engine is running at a higher RPM the water pump may be functioning, and when the engine idles, there may not be enough power to work the pump. The pump is responsible for the flow of coolant, and is also a common place for leaks. Find the source of the leak, and test the pressure coming from the water pump.