Foggy windows in 89 735i

Hi,

I have an 89 735i, it is the second one I have owned and have had this one about three years. The windows seem to fog up excessively. If it is raining out or I have one or more passengers in the vehicle I have to keep the defrost on and it only manages to clear the front window. If the car sits in the sun when it is a little cold out I have to take a towel to the windows before I can drive.

The heater core appears to be okay and the coolant level remains constant. I cannot find a leak or any moisture in the car to suggest a leak. I do not remember my last 735 having this problem. Do any other 735 owners have this problem? Is there a fix?

Mark

Have you checked the spare tire area in the trunk? also you may want to see if your sunroof drains are clogged or the cowl area below the windshield has leaves ect covering the drains or allowing water to seep into the car. Another thing to check is if the A/C condensate drain is cloggged.

This use to happen to me in an Rx7 Turbo a few years back, I found the clogged drain, and then let the car sit with Arm and Hammer in a box for a while to absorb the moisture.

also is the air conditioner working? if you are just using the heater without the ac compressor running, that will cause your windows to fog as the ac drys the air of humidity.

I have checked under the carpets and have checked the trunk and found no leaks or wet spots. I'll check the A/C though, good suggestions.

Any rust spots on the body? Check all door seals too. Could also be related to drainage passages as stated above that collect moisture.