Coolant and washer fluid tank sensors don't like the cold?
12-11-2010, 07:05 AM
#1
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Coolant and washer fluid tank sensors don't like the cold?
With the recent cold snap we've had, a few times in the past week when I do a cold startup I have a message in the dash that says to check the coolant level and the washer fluid level. If you look at them, the levels are just fine. If you restart after the car is a little warmer, the messages are gone. Anybody else get these false readings in the winter from these water based sensors?
12-11-2010, 07:09 AM
#2
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2018 GLC300 4Matic; 2005 C55; 2003 360 Modena
Maybe both tanks look fine, but are just at the level to trigger the warning sensor. With heat comes expansion and the levels rise enough to satisfy the level requirement for the warnings.
Last edited by kjb55; 12-11-2010 at 07:11 AM. Reason: spelling
12-11-2010, 07:57 AM
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C32
I get an intermittent "coolant leve" visit workshop message. I can't figure out why or what causes it to come on. At first I thought it came on when the engine was running hotter than normal, but sometimes it comes on when the vehicle is cold and isn't even warmed up.
01-31-2011, 10:38 AM
#6
Super Member
@Viper: I just encountered this problem for the first time Saturday night. I started the car and after driving for about five minutes the "Coolant Check Level" kept flashing on the information display screen. The temperature at that time was 24 degrees F. I checked both the coolant and the windshield washer fluid the next day and both appeared to be full (75% - 85% capacity). Driving the car the following day the "Coolant" indicator did not display again. Perhaps this is the same problem you encountered? Did the Coolant indicator continue to show up on your C55?
01-31-2011, 08:09 PM
#7
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Yes, it has definitely come back many times. I looked through my service manual this past weekend and noted that it said the level is supposed to be at crack between the top black plastic and the lower white plastic. Mine is about an inch below that, so yes I'll assume that over the past 5-6 years some has disappeared, been consumed, etc. I'm just going to add a little water, it shouldn't be a problem. MB recommends keeping the ratio around 50%, but if you're above 40% you're fine. I honestly think you can go lower than that based on their chart.....
