How do you test a heater core

[Kibokojoe]

How do you test a heater core?

[Blitzkrieg Bob]

How do you test a heater core?

run the heater and sniff around for the lovely scent of coolant, run the defroster and look for vapor on the glass (note lovely scent of hot coolant in the air)or if it's real bad... look for steaming puddles in the front foot wells.

Also it may leak out by the fire wall, so drops of coolant will appear on the ground near the area on the firewall.

[shogun]

If it smells swet, your heater core is gone.