Pinto Car Club of America

Hello all ! !
My '76 has got INCREDIBLE window film/gunk/yuk that is getting to be a dangerous condition when it is cold outside.
I have tried to clean it, and we are starting to make a dent, but it is an uphill battle.
Is this caused by a leaking heater core blowing up thru the defrost vents?
At times it will blow some funk out of the dash vents.
Thanks,
Mike

How often do you have to remove the gunk?  I clean maybe once a year, but nothing is ever heavy enough to cause a problem.  Therefore, I hate to say it probably is the heater leaking.  You could bypass the heater core with a section of hose under the hood, and blow out the coolant remaining in the core.  Clean the W/S and see if the gunk formation stops.  
I take it you have an A/C car?  Any funk coming out the vents is likley to be coolant residue.  The above test will help pinpoint the cause, but this IS a bad time to stop using the heater!

Other possibility would be a large buildup of wet, decomposting crap (leaves, dirt, dead stuff, fungus, etc) in the heater box.  

My test: I would run my finger through the gunk and touch it to the tip of my tongue.  :o :o If it has any sweet taste, it is coolant.  
Yep, i know what most auto fluids taste like...  :hypno: :hypno: :hypno:  Taste a tiny bit - don't drink!!   :lol:

Time to open the heater box. In the process of restoring mine, I found it full of leaves, twigs, fabric, and plenty of dirt. It's amazing how much crap will collect in the box after 30 years...and there's really nothing to keep it from getting down there.

Chris

If it's anti-freeze (and I suspect it is) it will have a sweet smell and will make the glass greasy. The steam from the defroster vents and the fogging of the glass is a dead giveaway.