Heater Problem

[Corey170]

i have a 91 ford mustang (4 cyl automatic). every time i try to turn the heater on the windows fog up and it really stinks. howver when i turn on only the fan (without heat) the windows dont fog up at all. Is this a problem with the heater core or something along those lines? I just dont want to replace a part that doesnt need replacing and waste my money. anything would help.. thanks

[Scottoldboy]

Originally Posted by Corey170

i have a 91 ford mustang (4 cyl automatic). every time i try to turn the heater on the windows fog up and it really stinks. howver when i turn on only the fan (without heat) the windows dont fog up at all. Is this a problem with the heater core or something along those lines? I just dont want to replace a part that doesnt need replacing and waste my money. anything would help.. thanks

I just purchased a similar car for my daughter and fortunately don't have this problem - yet. I've had Ford cars for 30 years and say that the odds are nearly 100% that the heater core is leaking. Most heaters have a door to regulate the heat and with the heat off, the door is closed and keeps the air from passing over the wet heater core. With the heat on air passes over the heater core and it picks up moisture and smell. Even when the car is fully warmed up you can't get rid of the moisture that will condense on the inside of the windshield. You might try some Solder Seal stop leak, but it's difficult to avoid the inevitable, replacing the core. - Scott

[KimMG]

Be aware coolant fumes can be toxic. If your heater core is leaking, you may want to bypass it until you get it fixed.

[doommarine44]

Very sadly, sounds like a heater core!!.. Ford taurus's are notorious for this (thankfully mustangs arent!!) and I have seen it many times in them.. it smells very odd. like burnt sugary somthing.. these things are beasts to change but must be done.. can cause you to lose coolant and overheat!! Yikes!!

As a side note.....

I have tried Bars Leaks Seal tabs on a taurus with a smelly heater core.. it worked well on it.. however it was a 99 model taurus, yours might be rusted out quite badly.. and personally using bars leaks seal tabs scare me, as it made the taurus over heat until i shot water into the upper radiator hose!

[Corey170]

yeah thanx for all the help, i took on the grueling task of replacing the core. taking off the dash and lowering steering column and all. it was a bitch and a half but i finally have heat.. and not stikny heat at that. a lot of help from the website at cardomain.com seen in the techincal reference post and also chiltons helped.