So my washer fluid reservoir filled up with coolant this weekend, and I can't find a washer fluid heating coil in-stock locally. I was planning to remove the heating coil entirely and connect the inlet and outlet coolant hoses together. I use the -20*F washer fluid and live in the South, so I might stick with this shadetree solution indefinitely. Any danger or risk in doing so?

Only reason I ask is because of the thermostat/thermovalve attached to the heating coil. I don't want to disrupt the flow of coolant to the engine by connecting the hoses together. Coolant flow and washer fluid temp is tightly regulated between 20-30*C in the factory setup.

Thanks as always.

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1982 300D-T (sold)
1988 300E (sold)
1994 E320 Wagon (sold)
1995 E320
1998 E300D-T
1999 E3204M Wagon
2001 E320
2005 E320 CDI

Should be fine...did that on a 92 300D. Really don't need the heated washer fluid in the South.

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 157k miles
06 E320 CDI "Rutherford", Black on Tan, 175k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 144k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 70k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

It is better to block the hoses than connect them together. Connecting together lets hot water to bypass the radiator.

Find where the hoses to and you may be able to eliminate the $$ molded " T " hoses if your car uses them. Your car might have a plastic T in the heater hose at the firewall, changing this to a non T may be possible if this body style ever came that way. Also look for a heated windshield base, you can block it's water source as well.

I blocked / changed hoses on my 97 SL320 since it never sees winter duty, car acts the same as my 97 C280. ( same engine series )

If your car has heated washer tubing and nozzles, they will still work as they are electric.

My 99 heater coil leaked antifreeze into the coolant and smeared the windshield. I looped it with a short copper tube with no ill effects. Blocking sounds good to.

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1999 Mercedes E300TD daily driver sold at 238K miles 106K miles were mine, rust worm got it :-(
2006 Mercedes CDI new daily driver! 56,000 miles May 2016 now 85,625 Apr 2018 and Apr 2019 101,000 miles Apr 2020 109,875. March 2024 135,250, Dec 2024 145,000 miles