As soon as I turn up the temperature, even without turning on the fan, a grey-white oily mist starts blowing into my cab from the driver's side vent near the window -- not the defrost vent. My brother detected an odor of anti-freeze. Has anyone dealt with this? Thanks for any light you can shed!

Edited December 20, 20169 yr by lornafear

if it smells like toasted marshmallows - that is coolant.

 

 

details on car please - if it's an older car, I might be tempted to try a bottle of the Subaru Coolant Conditioner (it's a type of stop leak) but, I have doubts it would solve a heater core leak.

 

pulling the dash or bypassing the coil with a hose-loop of some type may be the best choices.

Agree with Lucky Texan............sounds like a leaky heater core. If it is an older car, then tempted to go the radiator stop leak additive to the coolant system. You run the risk of plugging up the heater core to the point that there could be reduced or no heater warm air output. However, it should stop your antifreeze leak.

 

If your car is newer, then it makes more sense to have the heater core replaced. That can be expensive, because it is labor intensive, but it is the thing to do on a newer car.

Sounds like the heater core has a leak. A stop leak product might stop the leak, but it might also clog the heater core which will cause overheating of the engine.

 

Pretty much every Subaru you have to pull the dash out of the car to get to the heater core.

Try the Subaru coolant stuff like Texan said. That's the least likely to clog the core. (IMO)

Thanks for your input, everyone. My car is a 96 Subie Legacy L with just over 200K miles. I bought it from the original owner about 100K miles ago, for just $1550. I think they were selling it cheap because they'd spilled a pot of curry in the back. That was easy to clean up, and it's been a great car! No upholstery tears or wear spots, no dash cracks or marks, great A/C. The only thing wrong when I bought it, was a little dent near the fill cap and too much oil per the dipstick.

Replace the heater core immediately. Breathing coolant can cause serious health problems.

Are you loosing coolant?  Are you checking?  If you have a heater core leak, then you are loosing coolant and that could lead to an overheating event.  You do NOT want an overheating event, I think everyone here will agree with me on that.

 

If you are loosing coolant, the first thing I would check it the heater hoses where they connect to the heater core under the hood.  The reason is that they are a lot easier to get at.  If they are leaking at the connection, it is possible that some coolant could be following the pipe into the heater compartment.  If so, that is a lot easier to repair than replacing the heater core.

 

If the leak is very tiny, check to see if the AC drain is plugged up.  I don't know about your specific vehicle but often the AC evaporator shares the same compartment as the heater core in vehicles that have an external heater control valve.  That is a heater control valve located under the hood in the heater supply hose.  Cleaning out the drain would drain most of the coolant so you don't get the fumes inside the vehicle.

 

If all else fails, then use a 5/8" nipple to join both heater hoses together so that the heater core is bypassed.

Thanks for your input, everyone. My car is a 96 Subie Legacy L with just over 200K miles. I bought it from the original owner about 100K miles ago, for just $1550. I think they were selling it cheap because they'd spilled a pot of curry in the back. That was easy to clean up, and it's been a great car! No upholstery tears or wear spots, no dash cracks or marks, great A/C. The only thing wrong when I bought it, was a little dent near the fill cap and too much oil per the dipstick.

 

.................snip................. and too much oil per the dipstick.

 

That may be a red flag for some improper servicing. Have the front diff and transmission fluids checked for level and quality. It's easy for some folks to confuse themselves when draining and filling fluids on Subarus.

I immediately had hoses reconfigured to skip the heater core. Haven't been driving the car much and have  saved enough to have the heater core and pipes replaced.

 

My tranny just started hunting! Should I start a new thread?

I immediately had hoses reconfigured to skip the heater core. Haven't been driving the car much and have  saved enough to have the heater core and pipes replaced.

 

My tranny just started hunting! Should I start a new thread?

Yes, start a new thread re: your tranny to seek advise.