Cleaning Windshield
 

I have no idea what is going on with the windshield of my 1987 911. Ever since I bought the car in February of this year, the windshield gets a film on it, both inside and out. I can it and it is nearly impossible to clean without streaking. Then, in a day or so, a film reappears. It is making me crazy. I have tried numerous cleaners.... even vinegar. I can get it clean, but it always films back up. Any advice?

I use regular window cleaner from the shop, then I wax it.

Are you driving the car in the time the film is reappearing? Your heater system could be putting oil smoke in to the cabin, causing the residue. I have the same problem with mine. I THINK I finally figured out the stupid controls to turn off all air entering the cabin.

Sounds like Rain-X and/or ArmorAll...

Considering HVAC setting as mentioned, also ensure your heat exchangers/hoses in & around engine for heat are absolutely tight & in good condition, clear from any allowable intrusions of engine oil and fumes. However slight & tiny any cracks, openings or misaligned/loose connections there might be, will make it possible for burnt oil/fumes & even smoke :eek: to make there way into the cabin as that same residue collecting on windshield. You should (when needed in winter) be able to keep warm air/defrost setting @ desired setting "without" any fumes/oil residue entering the cabin if all components are in top shape. Check it out to be safe. ;)

Thanks for the advice all. It sounds like the "oil smoke" coming into the cabin is probably what is going on.

I had this issue on my 87 as well.

Drove me nuts until I got after all the leaks. All the usual suspects were leaking including the heat exchangers. The HE had a film of oil on the top sides. Cleaned these and a few months later I noticed the interior windshield glass stayed clean.

Didn't figure out the correlation until chatting with a buddy about it.

Isopropyl alcohol is pretty good at removing oil film from glass.

Oil fumes account for the interior film; I'm guessing you've got Rain-X on the outside if that is also building a film. Rain-X starts to film over when it wants to be renewed.

It could be the cleaning / preservation products applied to the interior and seats.

Film on the inside of a windshield comes from products like Armor-All gassing out. Use a micro fiber towel to clear it away.

Try this: never leave the car with windows fully closed, the fumes & heat build
up will do that. I always roll down my window by 1/4" on both sides to let the
interior breathe

Exactly why all HVAC has been removed from my SC Targa ;)

My '89 had a similar condition, where it seemed there was a film on it - you could wet it and it would appear to go away until it dried. In the end I replaced my 20+ year old windshield and it was well worth the effort - best maintanence I ever did! Having a clear pit-free windshield really improves the driving experience. Now it's been 50k or so miles and it's starting to pit again a little :-(

Chuck.H
'89 TurboLookTarga, 364k miles

Clean it with white vinagar and water 50/50.

Try using a fine finishing polish, the type you would use on your paint, if there is something on the glass it will take that off and leave you with a real clean windshield.

Has anybody ever tried "soft scrub" kitchen cleanser? Shouldn't hurt glass.

I routinely use "Bon Ami" or "Bar Keeps Friend" on the exterior portion of my windshields. They do a really nice job of removing road grime and oils. I also really like Eagle One Glass Cleaner for the interior and polishing the exterior. It is ammonia free and thus doesn't streak when hit with water. It works well on PC and smartphone screens too.

Vinyl off-gassing. Certain products can accelerate the gasses given off by the vinyl in your interior. I have found that as mentioned above armour all,is one of the worst. Also it seems that when the interior heats up and you keep your windows up it is worse as well.

To counter off gassing I simply wipe the interior with a damp rag, and don't park in the sun. When it is in the garage I keep the windows cracked open.

Another thing that helps is a dash cover.