Heater only putting out lukewarm heat

Hi,

It could be a few things. First, make sure the engine coolant is full and clean. Next, pay attention to the engine temp gauge and see if it is warming up to operating temp.

If the temp is correct and the coolant is full, allow the engine to warm up while the heater is on high. Feel both heater core hoses where they attach to the core at the firewall under the hood. They should both be hot. If one is and the other isn't the heater core may need flushed.

If both heater core hoses are hot, then the problem is most likely related to what is called a blend air door actuator. That component is inside the vehicle and under the dash;

Here are a few links that you may find helpful and of interest. Listen, check the few things I mentioned and let me know what you find. I can walk you through this repair once I know what is happening.

https://www.2carpros.com/articles/replace-blend-door-motor

https://www.2carpros.com/articles/car-heater-not-working

One last thing. If you could, take a pic of the heater hoses where between the front of the engine and the heater core. Some of these had a heater control valve. A bad one can cause this too.

Let me know.

Joe