Hello guys,

Something weird is happening to the windshield on my '96 Z28 (OEM as far as I can tell). I clean it inside and out and 3-4 days later the inside shows a greasy residue and fogging that really causes a lot of glare, specially when driving facing the afternoon sun.

I thought it was hot air coming out from under the trailing edge of the hood, causing this effect because the inside of the glass was colder from the A/C. This is not the case because there is this greasy residue the smears all over the place when I rub it with a paper towel. Some other facts:

-I live in AZ where there is almost no humidity. I can't recall this happening when I lived in humid FL.
-I have tried cleaning the interior of the windshield with: glass cleaner (with and without ammonia), vinegar, alcohol, just water and a paper towel with lots of rubbing and then a dry one.
-I have always used leather care products. Could this be evaporating and causing the residue? it only happens in the windshield not the other windows.
-Do I need to change the dryer in my A/C? the system works well and is not leaking or losing pressure.

My windshield has some deep streaks on the outside so I was even thinking of getting full coverage insurance and cracking the glass to replace it but I don't know if this will cure the problem. seems like any glass would be affected.

Anyone else has suffered this? I have to clean the glass every 3-4 days and you know it's not easy to do on 4th gens...

 

I'd try changing brands of the leather cleaner and any other interior cleaners you're using.

 

Do you smoke? That will cause a real bad film just as you are describing. That is the only thing that i know of other than your heater core leaking into the car. You will probably be able to smell the anifreeze and the carpet may be damp from it.

 

This fogging you describe is a common symptom of the heater core starting to leak. Do you smell coolant inside the car while driving, especially with the heat or defroster on?

 

It might be one of your car care products. I once had my old Z up at a dealership for PCM issues, and my buddy decided to detail the car for me while it was there. When I got it back, the windshield kept greasing up like you described. He used some super greasy **** that the dealership had to do the interior plastic, and it made a helluva mess.

 

I do not smoke. The heater core seems fine; there is no antifreeze smell or leaking in the passenger footwell area. I've used the heather only a couple times in the winter, right now the summer temps are 105-115F here so it's just the A/C.

It never rains here so its not like the T-tops are leaking and then the water condenses in the windshield. When I wash the car I'm always careful around my T-tops seals anyway.

I'll try Napa spray cleaner which I think it's the best and I got a windshield cover now to cut down on the interior temp when the car is parked. The car already has tinted windows and I bought the factory T-top inserts a long time ago to cut down on the sun and heat when I lived in Miami.


Thanks guys, if anyone else has more ideas...