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Q: Heater blows cold air

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Put the heater on and it shoots cold air. Playing between hot and cold dial along with fan speed the air will get hot air for a bit then back to cold. At the same time the temp guage rises. Then goes down once I turn the dials off. Sometimes temp stays up

My car has 1180000 miles.
My car has an automatic transmission.

If the temperature it rising, most likely your car is low of coolant. The best method to check your cooling system is to check it in the morning when it is the coldest. Remove the radiator cap. The coolant should be all the way to the top of the radiator filler neck. If is not, fill it all the way to the top, install the radiator cap and top of the coolant overflow container. Test and see if the heater performance is working properly. Keep in mind, there may be air bubbles in the system that will require you to do this several times.

Before you get to carried away with the air bubbles, you should locate the source of the coolant leak. If a cooling system is low, it has a leak.

If the cooling system is full and with these symptoms, then you primarily have an overheating issue. An overheating motor can create air bubbles in the system that don’t allow coolant to travel through the heater core. Some things that can cause overheating are, clogged radiator, failing thermostat, water pump impeller failure and a blown head gasket.

The biggest problem is the overheating, so I would address this first, unless it has to do with a low coolant issue, which taking care of a coolant leak is taking addressing the overheating. If it is determined the cooling system is working properly and you still have heat issues in the cab, the next things to suspect are climate controls.

If your Acura has automatic climate control, diagnosing this becomes much more complicated requiring expensive equipment and years of experience to diagnose. I recommend the following inspection to help you out; Heater is not working inspection Be sure to send the technician a note explaining your symptoms when you book this appointment.

Good luck!

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