Car: 1989 260E
178,000 miles

Today, after a fairly short highway drive, my car began to run hot -- a steady 105 degrees or so -- as a result of sudden coolant loss. Upon opening the hood, I was shocked to see steam rising from the wiper fluid reservoir -- which was filled to the top with the very hot, "lost" coolant!

The coolant expansion tank was also sort of buzzing, as if under high pressure -- or perhaps negative pressure, and I additionally noticed saw that the plastic tube on the passenger side edge of the hood that feeds the washer jets was ruptured.

Before I pull out the tools, is the following diagnosis correct? :

I assume the washer fluid heating coil is ruptured as well, and I will try to fix or bypass it. This would explain why, when I refilled the washer reservoir about a month ago, I lost about 75% of it by the next day -- with no leakage to the ground. I assume it was sucked into the cooling system, and coolant was also being pumped back into the reservoir -- accounting for the unusually oily streeaking when I would use the washers.

From reading various threads here it seems bypassing the washer fluid heater coil is no big deal, but before I do that, is there anything else I should be considering?

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2008 E350 4matic / Black/Anthracite

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Gone but not Forgotten:
2001 E430 4matic, 206,xxx miles, Black/Charcoal
1995 E320, 252,xxx miles, Black/Grey
1989 260E, 223,00 miles, Black/Black