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・Save up to 30%

Get a quote

What others are asking

Q: Car stalling when in drive

Hello. If the engine turns off right when you put it into gear, then it may have an idling issue or it may have a bad torque converter clutch solenoid. If the vehicle seems to jump forward when this occurs,...

Q: My heat and air turns on without a problem but does not blow very hard (heat blows harder than air). Rattling noise.

The heater and the air conditioner both use the same blower motor. However, Nissan does have two separate fuses for the same unit. One of them can be blown. There are also resistors in the system that can fail. There...

Q: Engine cooling fan works fully when it's cold

Hello. The cooling fan is activated when the temperature of the car reaches slightly above normal operating temperature. If the engine stays cool long enough, the cooling fans will not come on. If the engine gets warm but doesn’t overheat...

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...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
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.