I took my car in for a 90,000 mile service. Here is what was done: replaced serpentine belt and drive belt, adjusted valve and replaced valve cover gasket, replaced spark plugs, coolant flush engine oil exchange, and oil change. Since then whenever I turn on the defroster, a terrible smell occurs. I ended up having to make an 8 hour trip recently in 25 to 30 degree rainy weather and had to open the windows every so often in order to defrost them. Ended up with pneumonia! Just recovered and have to make this same trip again. Drove my car last night for the first time in the rain and problem still exists. When I took the car back to the dealer, they said they could not find anything wrong. Please help!
Sounds to me like the coolant flush exposed an already failing heater core. With your symptoms and a coolant system pressure test this can be diagnosed. The other possibility is the air conditioning condesate drain tube is plugged. If you have water leaking from under your lower dash, one of these conditions are present. If it is, does the leaking water have a sweet antifreeze odor? If it does, it’s a leaking heater core, if it doesn’t it’s probably a plugged drain.
Thanks so much for your insight. I am heading to the dealer now.