I have a 1989 260e and have been experiencing slight coolant loss. I had found nothing under the car or in the oil and was unsure as to where it was going until now. As the coolant level would go down the level in the windshield washer tank would go up. I removed the tank from the car and after removing the heated coil I found the "guts" of the "thermo valve" (I think that is what it's called) laying in the bottom of the tank. I reconnected the coolant line so that the heated coil is now out of the system. Is it necessary to have this part in the system? I live in Phoenix, Arizona and I don't have a real need for heated washer tanks or heated seats, etc. My other concern at this point is that fluid in the washer tank may have been drawn into the cooling system through that valve since that tank was acting like a second expansion tank. Is a coolant flush in order here? Please weigh in with any comments, Thanks Tom