Mechanics

CAR HEATER WILL NOT WARM UP

1994 Subaru Legacy • 4 cylinder FWD Automatic • 224,000 miles

I was warming the car and turned on the Heat/Defrost expecting to defrost the wind shield but only cold air came out.I hope this is a very easy fix?
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MistyF5109
August 13, 2011.



Feel the upper radiator hose. It should get too hot to hold onto for very long. If it's cool, suspect a stuck thermostat.


Caradiodoc
Aug 13, 2011.
Thanks for the tip. I was doing some research on my own and your answer was a repair that was recommended; also I was told to check my anti-freeze ratio in the radiator. I put a little more water than anti-freeze because my small radiator hose found a hole in it so my anti-freeze was about a third of a bottle so I put in more H2/O. So I will be flushing out that mixture and put in some good anti-freeze to see if that will fix the problem as well. Thanks again caradiodoc


Tiny
MistyF5109
Aug 13, 2011.
Hold on. If there was a leak and the coolant level was low, it's not going to circulate through the heater during prolonged periods of idling. You should find that you suddenly get hot air when you start driving. If that's the case, just fix the leak, fill the system, and be sure to watch for signs of overheating. If that happens, there's an air pocket that needs to be burped out. If that air pocket forms under the thermostat, it won't open. Thermostats only open in response to hot liquid, not hot air.

Having the wrong ratio of antifreeze to water won't cause overheating unless there's way too much antifreeze. Antifreeze doesn't hold as many BTUs of heat as compared to water. Water is better at carrying heat to the radiator, but antifreeze is needed for freeze protection and for the water pump lubricant and corrosion inhibitor additives.


Caradiodoc
Aug 13, 2011.
I will try what you suggested, Thanks again.


Tiny
MistyF5109
Aug 14, 2011.
This is my "baby" in question!


Tiny
MistyF5109
Aug 14, 2011.