This morning, I started my car and turned on the heater to let things warm up while I finished getting ready. When I came out to the car about 15 minutes later, the temp gauge was showing normal operating temperature but no hot air was coming in and didn’t for the rest of my 15 minute drive to a meeting. When I next drove the car about an hour later, I let the car warm up first, then turned on the heat. It started to blow warm air, but then after a couple of minutes, the air got cold again.
Tauruses are notorious for the coolant getting all brown and full of sediment. If the coolant is at its proper level then there is a good chance the heater core is clogged up. If that is the case a coolant system flush is needed.
The trouble could also be due to a air getting into the coolant due to a head gasket leak. Air gets trapped in the heater core and causes no heat to transfer.