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Q: heater blowing cold air most of the time, possible coolant leak

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My heater is all goofed up. I blows cold air and then hot air and then cold again. It keeps doing this the entire time it's turned on. I talked to a mechanic that said it's leaking coolant, so I filled up the coolant and I don't see it leaking. Do you have any ideas?

A few different items can cause the heat to be intermittent. An air bubble in the cooling system, low coolant, a heater core failure, a coolant leak, and an AC actuator can all cause the heat to go in and out. If you want to have this checked, a qualified technician, such as one from YourMechanic, will be able to perform any diagnosis your heater and perform any repairs required.

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