I have been noticing the smell of antifreeze inside my car while I'm driving. At night when I turn on the heater, the windshift instantly fogs up and I can smell antifreeze in the cockpit, lol. It's hard to get the antifreeze off the windshild because it's so oily. I put a new heater core in the car about a year ago ( pain in the bottom by the way ) and I don't know what else it could be. I looked around and don't see any antifreeze leaks, but I can sure smell it. I looked and felt on the passenger side floorboard and don't notice any fluids or leak down there. Someone help me, what else could the problem be? Where else would it leak and cause the smell and why would it come out of the defroster vents???? thanks everyone!!!!

 

The heater core is really about the only place that antifreeze can get into the pass compartment.

It doesn't matter if it's new, or how recently it was changed, or what; if it leaks, it leaks. That sucks maybe, but ..... that's just how it is.

Check to make sure the hoses are tight on it. If they leak, the antifreeze can run into the car through the little holes in the firewall.

If the hoses are good, then there's only one conclusion left.

It's easy to damage the hose nipples putting one into a car, by getting them hung up on something as it goes in, and crack the solder joints or other parts. Alot of heater cores that you can buy, don't have the hoses in quite the perfect place, and get into a bind going in; and those are especially likely to leak later on.

 

You have a leaking heater core, or hose.

The reason you are not getting moisture in the floor board is that the leak is so small that only steam is exscaping the core. The steam stays as gass until it reaches the cold windshield than it condenses into a oily fog.

 

Thanks so much for your help. You two are very informative & I think you may be correct. Are there any heater cores that are better to buy than others? Also, sometimes I get the antifreeze smell even with the heater off, is this normal. Is there always coolant flowing thru the core or just when the heater is activated? THANKS

 

I'm not sure what year it started, but some 3rd gens have a heater bypass valve located above the pass side valve cover. It's easy to find if your car has it. Just follow the heater hoses. The valve prevents coolant from entering the heater core when heater is not being used.
This valve sometimes gets removed when someone "repairs" the car.

 

So if I don't have this valve, then there is always coolant flowing thru the heater core? Anyone got a pic of what it may look like? How is the valve controlled?

 

I believe this is it.

the valve is vacuum controlled

 

Nope, I looked and I cannot locate that valve. I'm just gonna end up getting another heater core and going through the pain of installing it, lol. thanks