Engine overheating, heater blowing cold air?

2010 MAZDA 6
184,236 MILES
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JEA
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I recently flushed the coolant out of the car and now the heater is blowing cold air. Everything is perfectly fine except for the heater blowing cool air and engine overheating. Do I have to flush the coolant out again?
Nov 23, 2022 at 11:00 AM
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JACOBANDNICKOLAS
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Hi,

If you have no heat and it's overheating, chances are you have an air pocket in the system preventing the coolant from properly flowing or the coolant is low.

I attached the directions from my manual for bleeding/refilling the cooling system. When you do this procedure, have the heater turned on high so there is a good flow of coolant through the heater core. Also, you should be able to tell if there is heat starting to work.

Try this and let me know the results. Also, before anything, confirm the coolant is full.

One other thing. Was the engine overheating prior to servicing the system? If it was, did you have heat prior to the service?

Take care and I hope you have a good Thanksgiving.

Joe
Nov 23, 2022 at 9:45 PM
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JEA
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Thank you so much! Happy Thanksgiving! So do I have to flush the coolant out again or can I just run the engine and try it out?
Nov 24, 2022 at 7:18 AM
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JACOBANDNICKOLAS
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Hi,

I don't see a need to re-flush the system. I would just follow the directions I added above. You did nothing to create more dirt in the system.

Let me know how things turn out for you.

Joe
Nov 24, 2022 at 7:03 PM