koojo

The low windshield washer fluid light comes on in my GLK when the temps are below 32*F. When it's warmer the light doesn't come on. There's plenty of windshield washer fluid in the tank. It's been doing it for a few more months now, and does it even if the fluid level in the tank is mid level or full. Anyone else had this?

MKenM

Yep, it happened to me last winter. The light would come on when it was below freezing. I brought it to the dealer and they said, are you ready for this "it is the wrong fluid and doesn't protect to a low enough temperature".

I told them at the time that I was using Rain-X and they told me that they had to drain it and they refilled it with their brand. I never had the problem again. My question always was, how does a sensor that is supposed to indicate the lack of fluid measure the temperature of the fluid. I was always able to spray the windshield with fluid even when the indicator came on. They did not charge me but said that it was my fault.

I had reason to go to the parts department a couple of months ago and when I asked them about the fluid I should use he gave me a gallon of some blue stuff and said "here use this, this is what we put in all the cars." It was some no name blue liquid. He didn't charge me for it and while I was there he gave be a small bottle of "Summer Fit". There is also supposed to be "Winter Fit". They are just additives to help clean the windshield like detergent.

Like I said never had the problem again but still can't figure it out.

koojo

So what are we supposed to use when we need some fluid... MB windshield washer fluid? Wtf were they thinking? I am not going to the stealership to buy a gallon of blue water to clean the glass. This is the most rediculous thing I've ever heard. Way to drop the ball on that one MB.

So what do they recommend people buy? You can easily go through a whole gallon bottle in a few days if there is a storm. They can't expect people to buy their crap... grr

MKenM

It was just generic crap that probably had a better below zero rating. The blue stuff was called Splash and its good down to 20 below zero. At a retail of $2 and change you can't go wrong.

GLKKa2H

Yes, the error message came at temps from below approx. -7,5ºC (18,5ºF), as posted in another thread (there is now a number of them) on the subject.

I did as well refer to a Daimler internal info, addressing the issue, translated (in short) from Danish:
Cause: The electrical conductivity of the fluid is insufficient due to:
- Usage of distilled or "deonized" water.
- Amount of water (providing conductivity) in the solution i too small.
- The anti-freezing additive to high.

Electrical conductivity of water decreases for example 2% per 1°C (1,8°F). Assuming various washer fluid brands “behaves” accordingly, the conductivity of the fluid, with decreasing temperature, may finally “open” the fluid level sensor circuitry, thus triggering the display message.

An experiment would be (DON’T DO IT! ) adding a little salt to the reservoir to see if the message disappeared, as it would increase the electrical conductivity of the fluid, however the side effects -

We are using the MB Winterfit, for protection down to -18ºC (-.4ºF), mixed 1:1 with water. From the “The anti-freezing additive to high”, do I see why a higher concentration is not recommended – to prevent false Low Level Warning Display messages.

Quote:

Originally Posted by koojo

So what do they recommend people buy?

You COULD try adding a little (tap) water to the reservoir, thus reducing the mixture concentration i.e. increasing the conductivity, given the fluid still will provide antifreeze protection as required for your area.

koojo

Yeah I suppose I could give that a try.. but what a PITA. You would think that they would have put a better sensor in there for this very reason.

I have been using the -20*F fluid so next time I'll try to put some tap water in there, and hope it doesn't freeze.

GLKKa2H

Agreed! From a statement given by our dealership when they replaced the sensor in the reservoir (and the reservoir as well), does the issue apply for the C-Class. As cases are reported on forums for other MB-Classes as well – over some time -, should MB be well aware of the problem.

Our replacement sensor is most likely manufactured at specifications as for the original (another statement given). We haven’t seen the error message after the replacement, however have environmental temperatures only been down to the “critical point” – so far. We will see – and report

kyoshiro

it could be possible that the rainx's composition has some things that blocks the sensor because rainx is a derivative of glass coatings and the sensor prob had a build up, maybe.
Im happily using my 1z Krystal Klarr + 1z Antifrost Washer fluids