Originally Posted By: OVERKILL
Originally Posted By: HTSS_TR
OE thermostat should failed open not close, when it fails the engine running cold which may pollute a little more than spec but will not damage the engine vs failed close.
This. Plus, if the heater was not blowing hot air, that's not a sign of a bad thermostat, that's a sign that there's no coolant in the heater core. It probably ate a head or intake gasket, dropping the coolant level and overheating.
Originally Posted By: HTSS_TR
OE thermostat should failed open not close, when it fails the engine running cold which may pollute a little more than spec but will not damage the engine vs failed close.
This. Plus, if the heater was not blowing hot air, that's not a sign of a bad thermostat, that's a sign that there's no coolant in the heater core. It probably ate a head or intake gasket, dropping the coolant level and overheating.