MY or pt courser heat comes out warm then back to cold turn it back on warms up for awhile and then back to cold
It sounds like the heater system is okay but the engine temperature is not maintained correctly. Watch the engine coolant temperature on gauge and if you see that it is going up and down too much then have the thermostat replaced since it is most likely sticking and not controlling engine temperature and may fail completely in the near future causing the engine to overheat.
The lack of heat being generated by your system may indicate a clogged heater core. The [heater core]((https://www.yourmechanic.com/services/heater-is-not-working-inspection) is a small radiator like unit that circulates the hot coolant from the engine through the heater core which then uses this warm coolant to heat the inside of the car with the help of the blower motor that blows the warm air through the vents inside the car. The other possibility is that the thermostat may not be allowing the engine to reach a normal operating temperature and since the engine’s warm coolant is the source of the heater core supplying heat to the inside of the vehicle, this can impact the warmth of the heat inside the vehicle. I would suggest having an expert from YourMechanic come to your location to diagnose your heating system.
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