Windshield Washer Tank Heater '05 S600
Thread Starter
Junior Member
Joined: Jan 2008
Posts: 34
Likes: 0
'05 S600
Windshield Washer Tank Heater '05 S600
The washer pump stopped working. No big deal. Replaced it with a generic pump and a few months later that stopped working. Took it out and found the end of the pump in the tank had melted. I never thought about what temperature the the tank gets heated to. I haven't measured the water temp yet, but the lines to it are VERY hot to the touch. Is this heated water tempered anywhere? Should the tank water run at engine temp?
Thread Starter
Junior Member
Joined: Jan 2008
Posts: 34
Likes: 0
'05 S600
Problem Solved.... I didn't go far enough in the EPC. It turns out that the WW heater line is attached to the Rear Duo Valve. This valve also controls the rear heater, which, I knew was bad, it was passing hot water to the rear in the summer. Turning off the rear A/C stopped the symptons, so I didn't change it. I didn't realize it controlled anything else. Time to do it right.
Member
Joined: Mar 2014
Posts: 93
Likes: 22
2004 S600, 1998 M3, 1974 2002 Touring, 2006 Cayman S
Did you get any error codes when the rear system was used? I get a sporatic code in the HVAC system pointing to something in the rear and sometimes rear vents blow warm air instead of cold when AC is running.
