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windows won't defog & occasional smell of antifreeze in cabin

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We bought our '05 Outback XT this spring and as it is now winter, we turned the heater on for the first time this past week. Two days ago, I came out to find what looked like water on the inside of the windshield but when I went to wipe it off, it was sticky. When I smelled it, it smelled like antifreeze. I checked all around the dashboard and under it on the passenger side and found no leaks. So I drove home. Today, my wife and I headed out onto the highway and much to my dismay, the windows fogged up and stayed that way for quite a while. We eventually had to turn off the road and sit idling until they cleared off enough to drive home. Occasionally during the drive home, we'd get the sweet smell of antifreeze in the cabin. Anyone have any ideas as to what can be causing this?:mad: Thanks in advance for any one offering advice!

might be the heater core behind the dash, just throwing that out.

It is the heater core, and those fumes are not the best thing to be breathing in.

 

Put a can of Barrs stop leak to see if that stops the leak. It may fix it or boy you some time.

Your best bet is to dump in a bottle of the Subaru stop leak additive and see if that fixes the leak. It's approved for use on all Subaru's so it won't clog up your radiator, etc. The passages in a heater core are generally smaller though and the stop-leak stuff tends to clog them rather than fix leaks in them - either way it might stop the coolant loss.

 

Otherwise you are going to be pulling out the dash for a heater core change-out. Either that or loop the heater core hoses together and bypass the core for now - you could get one of those 12v heaters that plugs into the a power outlet.....

 

That's a very new Subaru to be having a heater core die like that - they are a pretty rare failure.

 

That just sucks - heater core swap is a large amount of work and the core itself is not cheap either. You are looking at about 6 hours labor and a pretty penny for a heater core - probably about a $1k repair unless you do that labor yourself.

 

GD

Edited by GeneralDisorder

  • Author

OH, I was so afraid of this! I had a look in the Haynes Manual for the car and saw how much work was involved. Yikes! She might end up at our local garage after all. *sigh* And why does this have to happen right before Christmas?:mad: Fortunately, my mechanic only charges $65 an hour. :) I was wondering if one of the hoses attached to the heater core had worked itself loose and that was causing the problem. The other question is...why would the heater core go so suddenly? As one of you said, the car is relatively new! Makes no sense. Thanks for all your offers of advice.

They can blow for any number of reasons - corrosion, over-pressure, manufacturing defect, etc. It will be pretty easy to tell what happened when you get the old core out - better than conjecture anyway. I would replace the radiator cap with one from the dealer just for good measure.

 

Too bad you aren't closer - I only charge $40 an hour :rolleyes:. But $65 is still much cheaper than most shops.

 

GD

SHops here in NY run from 85-110 an hour. The highest non dealer price i hhve seen is 110 and thats what they get for reading codes too!

 

My mechanic charges by actual time spent on the job, not book time.

It's your heater core for sure. I have a Merc in my driveway I only use during the summer because it had the same issue's. I just bypassed the core so I could keep driving it. I attempted to change it out once but eventually gave up because it was so far out of my realm. Some are very hard to do if you don't have the expertise and knowledge to tackle them. I tend to think the core was the first part they hung on the assembly line and they just built the rest of the vehicle around it. :-\ Sometimes electrolysis can be a factor with radiator and heater core failure. Check the PH in your coolant.

Edited by darsdoug
Excluded probable cause of failure.

I would try the subaru only stop leak first. DO NOT USE BARS LEAKS! Nasty stuff, does a number on every motor I have ever seen it used in.

 

Anyway, a black light and some die would help as well. It does sound like the heater core though.

If it smells like water/moisture without the glycol smell, it could also be just a clogged ducting drain line allowing evaporator condensate to back up.

 

Glycol smell kind of clinches it, though.

I have to agree with the guys...definately a heater core. The "symptoms" you state are classic ones for a leaking core. I also have to agree that repeated inhalation of ethylene glycol fumes won't be doing your lungs or organs any favors.

 

I have to urge caution with just using a stop leak compound for a heater core. I know, some of you guys have done this and it worked. Maybe so, but from what I've seen and experienced, if a heater core has so deteriorated that it starts leaking, it's time to replace it, not prolong the inevitable. Obviously, it's your car and money, but that's my educated opinion.

  • Author

Well, since I put up the first post, I've done a lot of reading...especially the operator's manual...and *blush* I'm a wee bit embarassed to say that if I'd learned how to operate the climate control properly, I'd not have fogged up the windows. Of course, my knowledge of climate control USED to work off the premise that if it's cold outside, you CLOSE out the incoming air and recirculate the warm air inside the vehicle. It now seems that we let outside air IN to the vehicle when we want the windows defogged. That kinda flies against human logic when we are talking about Canadian winters and temps in the -10C to -35C range! The last thing I want to do is let FREEZING COLD air into the cab! lmao. But there is still the issue of the smell of antifreeze. I'll keep monitoring it and see if there is any more smell. And I found out this morning that there is NO block heater! I guess Utah doesn't get winter. lol So I have to put one of them in regardless. Again, thanks for all your info and help. It is greatly appreciated!

The damp air is ok because the AC compressor runs with the defrost - that removes the moisture from the air prior to it hitting the heater core.

 

Though sticky, glycol smelling stuff on the inside of the winsheild is still a heater core problem most likely - regardless of having fogged up windows or not. :-\

 

GD

  • Author

Thanks for the advice and info G.D. I will certainly get the car in as soon as possible to find out what the problem is. Can't have this screwing with my Christmas! hahah Or having me stuck somewhere where there's no heat at all and it's -35!

Is it possible that the smell is windshield washer solvent rather than engine coolant? Maybe with the fresh air coming in from the cowl you get a whiff of the windshield solvent instead of coolant after using the washer for deicing / cleaning.

I had the same problem a few years back, and was able to stop the leakage permanently by adding Alumaseal additive to the cooling system. Don't add more then one package to the system, or it may block the flow of coolant through your heater core. It is worth using this product first, before tearing the entire dash out to replace the heater core. That is major and costly work.

 

It is best to drain, flush, and add new antifreeze first, before adding Alumaseal.

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