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Q: No heat when not pushing on gas

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My car warms up normally like it should but it barley gets heat or sometimes not at all when I'm pushing on the gas and when I'm stopped it's just blowing cold air I did a heater core flush last year it helped a little bit but still had the same problem if the weather gets a little warmer like 40-50 degrees the heat is hot and doesn't blow cold air as much but when it's really cold it's a struggle

My car has 167000 miles.
My car has an automatic transmission.

You may have a clogged heater core that may be prohibiting the outer linings of the heater core to get hot. As you know, the heater core is a series of tubes that the coolant runs through that generates the heat from the warm coolant after circulating through the motor. These tubes can occasionally develop a buildup on the inner walls such that when the heater core is "flushed" this buildup on the inner walls of the lines remains and still allows the coolant to flow through the heater core. As a result, the buildup on the inner walls prevents the temperature from rising to its capability due to the insulating effect of this buildup on the inner walls. I would recommend having an expert from YourMechanic come to your location to diagnose and replace your heater core.

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