[BigSurScott]

I have a 2017 GLA 250 4Matic, bought it this past summer. When I press the windshield wiper button to have it spray the windshield with cleaning fluid the wiper blades start up before any fluid is sent to the windshield. I live in the wilderness on a dirt road that is quite dusty in summer. I am ending up having to spray the windshield by hand as I am concerned about the dust scratching the windshield.

Is this a defect that I should have the dealer repair or just poor design. This my first MB after two decades of Subarus. Never was like this with my Outbacks. Nor my spouses new Crosstrek. Thank you.

 

[Wayne]

Just a thought ... The wash button doubles as a single cycle button. A soft touch operates the wipers once. A hard push operates the washer. Perhaps you need to engage the button faster to get the wash before the car thinks you're asking for a wipe.

 

[BigSurScott]

Just a thought ... The wash button doubles as a single cycle button. A soft touch operates the wipers once. A hard push operates the washer. Perhaps you need to engage the button faster to get the wash before the car thinks you're asking for a wipe.

Thanks. I did try this but with same results.

 

[Wayne]

Then I'm wondering if you have a pump problem that is either slow to get started or allowing washer fluid to flow back into the tank when not in use creating a void in the line that takes time to fill and allows the wipers to beat the fluid.

The second problem would be easy to check by asking for more wash just after the first wash.

Are you getting a full dosage of fluid when you request a wash? Is it possible something is partially blocking the line?

It may be time to let the dealer know your concerns.

 

[BigSurScott]

Thank you so much. I really appreciate your response.
I have found that pushing the button immediately after the first time has the same thing occur. Wipers engage prior to washer fluid being dispensed. It is still under warranty (is a certified pre-owned, but is still under original warranty) so I am going to make an appointment with dealer. Very helpful to receive feedback.

 

[David Jean]

I have pretty much the same behavior..

The wiper will always start moving before the washer fluid come out. You have to engage the wiper before the washer with the button.

 

[AMGowner]

Makes you wish you had the magic vision system of some of the higher end models... MAGIC VISION CONTROL adaptive windscreen washing system: Conjuring trick for outstanding visibility | marsMediaSite

 

[Wayne]

Just to be clear in comparison ...

Mine is a 2017.

When engaging washing the wiper does start immediately. At the same time the fluid pumps out and hits the windshield at half height unless I'm traveling at 120 mph or more.

But the fluid is on the windshield by the time the wipers reach it at that half height.

Fluid then gets pulled down to the lower half on the first full wipe.

I had never taken the time to be concerned about this. And I've never checked the nozzles to see if they can be adjusted lower. I know on some of my older cars setting the washers so they wouldn't shoot onto the car behind me at lower speeds was possible.

 

[mishroom]

I have the same exact behavior of my 2017 GLA45 AMG, of the windshield wipers as you described, pushed the button and wipers go first and the fluid dispenses on the windshield later. I never thought it may scratch the windshield, but definitely will use the windshield wipers fasted. But Mercedes replace them every service anyway.
I'm not sure if the timing of the fluid and speed of the windshield wipers can be adjusted, maybe collective complaints will trigger a recall of this problem.

 

[Laura]

I have a 2017 GLA 250 4Matic, bought it this past summer. When I press the windshield wiper button to have it spray the windshield with cleaning fluid the wiper blades start up before any fluid is sent to the windshield. I live in the wilderness on a dirt road that is quite dusty in summer. I am ending up having to spray the windshield by hand as I am concerned about the dust scratching the windshield.

Is this a defect that I should have the dealer repair or just poor design. This my first MB after two decades of Subarus. Never was like this with my Outbacks. Nor my spouses new Crosstrek. Thank you.

Just poor design, mine does it too.

 

[Huey52]

Not to be a Benz "fan boy" but all design is compromise and there's likely a reason for this specific operation.

I've noted riding behind some other brand SUV's that the spray starts first which causes some of the fluid to arc over the vehicle and to my dismay land on mine (usually just after a polish ). I'm wondering if Benz is just being more civilized in their approach and/or may consider it better to have the fluid hit the windshield so that it is immediately spread at the halfway point as Wayne describes.

As an automation engineer I often had to consider tradeoffs in operation such as this, in some cases knowing I wouldn't/couldn't please everyone. 🤷‍♂️

 

[David Jean]

My highly scientific test : New video by David J

 

[Huey52]

That's only a few degrees of blade rotation before spray commences. I would say quite good.

My highly scientific test : New video by David J