Skip the auto shop - Our mechanics make house calls

Q: I poured antifreeze in my car and it's still blowing out cold air when I turn the heater on

asked by on

I'm trying to use my heater and I noticed my temperature gauge was more than half so I put antifreeze in it, now it's fluctuating. Why isn't my a/c blowing heat?
Now it's in park and the temperature is at the halfway mark

My car has 110000 miles.
My car has an automatic transmission.

A: Hello. There are a couple of things to chec...

Hello. There are a couple of things to check here. When the antifreeze was added, was the cooling system thoroughly bled (with the heater turned to "Max" heat and fan? There could be air bubbles in the engine or heater core - which don’t transfer heat.

You mention the temperature at the gauge is "fluctuating". A properly working thermostat should keep the temperature steady at the middle of the gauge. It’s also possible your heater control valve is malfunctioning, not allowing hot coolant into the heater core.

I would recommend having an expert inspect the heating system in order to pinpoint the correct repairs for your situation.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Grinding noise while driving 2006 Pontiac Torrent

Grinding noises can be caused by several things. The most common are brake pads that are worn to the metal. These will cause a grinding sound as the rotor rotates and rubs against them. The other common cause is bad...

Q: Heater won't work

The lack of heat being generated by your system may indicate a clogged heater core. The [heater core]((https://www.yourmechanic.com/services/heater-is-not-working-inspection) is a small radiator like unit that circulates the hot coolant from the engine through the heater core which then uses this...

Q: Service light on, high temperature, heat off

The only way to gain insight as to what happened it to retrieve the diagnostic trouble codes associated with the Check Engine Light. Even if the Check Engine Light is not on anymore, you may be able to retrieve history...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.