
I doubt it’s absent, but if you’re not getting heat, then yah, maybe the core is blocked. My cousin was having trouble with heat on his Tundra, put in a new heater core and it was blocked off within days. We took it out and cut it apart and some goop had immediately closed off flow. Still mystified what reaction built the goop, maybe incompatible coolant types.















I think there was something about a tan suit.