Blowing Cooler Air when on 77 degrees

[NWSKIUrbanRunner]

This is weird. When i have my thermostat at like 75-77 degrees it feels like its blowing more like cooler air than warm. Now if I crank it up to 80+ it will begin to blow warmer air. Is this normal or is the heater core going out...which would be a *****.

 

[CookieRoe]

This is weird. When i have my thermostat at like 75-77 degrees it feels like its blowing more like cooler air than warm. Now if I crank it up to 80+ it will begin to blow warmer air. Is this normal or is the heater core going out...which would be a *****.

Obvious questions before one can help you correctly:
1) Is the carpet wet on the passenger side? If so, you heater core is ca-put
2) Check you radiator fluid level? If low, fill up with toyota OEM stuff.

 

[MikeInNH]

Set it to it's maximum setting and check how much heat is coming out. Does it feel as hot as before this problem was happening.

First to check is radiator fluid. Be careful and wait til the engine has cooled down.

It could be a problem with the blending door. Most modern vehicle heating/cooling system adjusts the temp by blending in cooler air. If it gets stuck then it may not be opening enough and letting in too much outside cooler air.

 

[Adumb]

possibly could be a blend door issue

EDIT: Didnt see Mikes response