I'm pretty sure I already know the answer to this... but let's see if the replies concur or not.
'90 300TE:
Noticed last Fall that when I used the washer jets that I was getting a smear/film when dry on the windshield. I topped off the washer tank and it happened a few more times after. My best guess was that the washer heater was leaking antifreeze into the tank. I forgot about it.
Now that it's winter, and we
finally got snow/rain, I noticed that the smear/film was getting worse. Now it's bad enough that I
have to clean the windshield by hand to even see out of it, after using the washer fluid/jets.
So this morning it was bad enough that I stopped at a gas station on the way to work to clean the window... I also wiped off the wiper blade for good measure. Curious thing was the stuff coming off the blade was
black!
Got home from work and noticed the fluid in the washer tank is black
I have ALL the service history for this car and at no time was a head gasket replaced. There is NO oil running down the block, and I can't really "see" any antifreeze in the oil. No foam under the oil cap. Overflow tank is too old and crappy to really see the antifreeze color. No steamy exhaust or smell.
So I'm inclined to believe that the washer fluid has oil in it, that it picked up from tainted antifreeze that is leaking from the washer fluid tank heater.
Any thoughts?
I've always said that if the m103 gives up... that a om602/603 is going in it's place.