[krishnakumar]

Hello BHPians and TBHP readers!!

I had earlier posted regarding an annoying behavior of the rear wiper/washer of Mahindra XUV300 in the Official Review thread (click here for the same (Mahindra XUV300 : Official Review)).

When the wiper stalk is depressed, the wiper starts before the washer sprays water. This results in the wiper doing a full swipe (dragging all the dust and debris) across the rear windshield before meeting the water on its way back.

I noticed this annoying behavior right from day 1. At first, I assumed there was no washer fluid and that there could be a separate tank for rear washers (since no water was coming). Later, I realized that by continuing to keep the stalk depressed for a second the water comes out.

This essentially nullifies the use of washer if the wiper is anyway doing a full swipe without any fluid.

Obviously, I took the car to the service center to have a chat with the technical manager. He noticed the problem and said that it is a behavior in the MBFM itself and is likely due to the washer motor being in front. So the water is getting pumped at the same time as the start of wiper. However, since the water line has to build up pressure, there is a delay of 1-2 seconds within which the wiper does a full swipe.

I insisted on getting this checked on other cars and luckily there were 2 other XUV300s that had come for service. What I noticed was interesting. One of the cars had this wiper/washer working perfectly!!

Please see the videos below:

The annoying behavior served to you on a silver platter!

https://youtu.be/b0MZ28CkraY

Note: the above car is not mine but the behavior is identical in my car

The XUV300 where this works perfectly

https://youtu.be/hDcygT4HcTs

From this we confirmed that the problem is isolated to some cars. The only difference we could find was that the XUV300 in which this was working perfectly was a BS4 version and the other car (including mine) are BS6. The hypothesis is that the MBFM has this calibrated incorrectly in the BS6 version.

While I posted this on the official thread, there were very few responses on it confirming the behavior in their cars.

BHPians ashishk29 and Goandiaries confirming the presence of this behavior in their cars - LINK1 (Mahindra XUV300 : Official Review), LINK 2 (Mahindra XUV300 : Official Review).

And BHPian mihir_m13 calling out a possibility that this existed - LINK 3 (Mahindra XUV300 : Official Review).

The reason I'm starting a new thread is to bring attention to this problem and get a poll among XUV300 users (or BHPians who have XUV300s in their friends or family to check). The issue is small enough that a dealership would never bother bringing this up to Mahindra. For Mahindra, this might either be one of those known gaps small enough to not bother fixing, or they are completely oblivious to this bug.

In either case, I would like this thread to get the attention of the right folks. All it probably needs is one MBFM update with the wiper/washer motor calibrated to ensure the water comes as soon as or immediately before the wiper initiates the swipe. It already works for some of their cars - so maybe if it reaches the right ears, all it might need is a Ctrl+C and Ctrl+V.

Request to Mods:
* If this doesn't deserve a dedicated thread, please do merge with an existing thread.
* If you know anyone from the Mahindra's technical teams, please do help in bringing this to their notice.

[sagarpadaki]

There will be a one way check valve/non return valve installed after the washer fluid motor. That check valve ensures that the water remains in the pipe and does the flow back into the container. I think the check valve is faulty. Hence the delay in the water reaching the rear glass outlet.

I presume this happens only if you do not use the rear wash for a while? Maybe a few hours?

Get the valve replaced and see if the problem goes away

[krishnakumar]

Originally Posted by sagarpadaki

There will be a one way check valve/non return valve installed after the washer fluid motor. That check valve ensures that the water remains in the pipe and does the flow back into the container. I think the check valve is faulty. Hence the delay in the water reaching the rear glass outlet.

I presume this happens only if you do not use the rear wash for a while? Maybe a few hours?

Get the valve replaced and see if the problem goes away

Interesting. Thanks for your inputs.

However, I have seen the issue to be persistent even on repeated usage. If it's a check valve fault, would the issue persist if I'm using the rear wiper washer back-to-back? As of now, the issue exists even if I'm repeating it within a few minutes itself.

[sagarpadaki]

Originally Posted by krishnakumar

Interesting. Thanks for your inputs.

However, I have seen the issue to be persistent even on repeated usage. If it's a check valve fault, would the issue persist if I'm using the rear wiper washer back-to-back? As of now, the issue exists even if I'm repeating it within a few minutes itself.

Depends on the condition of the valve. Cannot say for sure. I suggest you replace that part and see if the issue gets resolved. Valve cost will be cheap. Max 100 bucks

[shancz]

Based on the video I see that the problem car's spray seems pressurized while the one that works fine has a more free flowing nature. Could that indicate anything? Was it common in all other cars you checked ?

If yes then probably a blockage in the piping/nozzle which causes the lag ?
Could it be due to a motor going weak ?

FYI the wagonR (2016) has the same behaviour and it has the free flowing nature, worse flow than the 300 of course.

Although what your ASC explained is what I had thought too.

[omranga98]

I have this lag in my Polo too.

The water motor (pump?) starts the moment i push the wiper stalk but it sprays after 2-3 seconds delay. Probably because the pipe line has air or the water flows back towards the front of the car and the motor has to pull the water back towards the rear before it starts to flow?

[scorpian]

The water motor (pump?) starts the moment i push the wiper stalk but it sprays after 2-3 seconds delay. Probably because the pipe line has air or the water flows back towards the front of the car and the motor has to pull the water back towards the rear before it starts to flow?

This above is the answer!! If you fill the line full and then use the stalk water would pour immediately. This behavior that you mention is common across many cars and is not to be worried about.

[krishnakumar]

Originally Posted by shancz

Based on the video I see that the problem car's spray seems pressurized while the one that works fine has a more free flowing nature. Could that indicate anything? Was it common in all other cars you checked ?

A very interesting observation indeed!

There were 3 XUV300s in the ASC when I visited (including mine). The videos that you see are the 2 cars other than mine.

My car (and the car on the video with the lag) have a pressurized flow - identical behavior with no variations. The car on the video is a much older car as well (I think late 2020 or early 2021), although BS6. Whereas mine is Nov'21 manufactured.

Since both my car and the car with lag has pressurized output, I don't think it's a defect with something blocking the nozzle.

Also, repeatedly using the washer does not change the behavior. If it was a drop in pressure or water receding, a back to back application should ideally see the lag reducing or going away in subsequent attempts, right?

I haven't tried changing the check valve yet as suggested by BHPian sagarpadaki, but it's something I'll attempt to do.

[H_Dogg72]

I think this is more luck of draw, my polo is fine, creta is horrible. Long ago wagon r was similar

[DevilzzzzOwn]

I have a BS4 3OO and it has the same behaviour. I am not concerned about it since I don't just use the squirt for short bursts. I usually pull the stalk for about 3 seconds which makes sure that there is a clean windscreen at the back with an additional swipe.

What I am more concerned about is whether permission was taken from the owners of the cars in videos that you have posted. With so many frauds happening, is it prudent to post someone else's car's number plates? If it was your car, would you put the plates? Just because it is someone else's car, is it okay?

[apachelongbow]

The normal behaviour should be that the motor runs, the water flows down the windscreen and then the wiper sweeps. Since cars don't have a sensor to detect a wet windscreen (rear screen), therefore they use a timing mechanism to synchronise the operation. Sometimes the sync can go wrong as we see here.

[Goandiaries]

Yes, this is happening in my BS6 Dec 2020 version as I've mentioned in the review thread. However, I didn't take it up with ASC proactively. What I have observed is that the rear shield gets dirty only during the highway runs especially during monsoons/rainy weather. Other days it remains relatively clean. During rains, I often use the rear wipers to maintain visibility and this prevents build up of too much muck on the windshield. Yes, it degrades the wiper blade, but I still haven't noticed any streaking and it is running on stock blade. The front ones were replaced at 20k service as it was leaving annoying streaks.

Coming to the point - yes, it would be great if Mahindra takes note of this minor bug and issue an update!

[abhi9044]

I have experienced similar behavior in my WagonR too. What I do to overcome this problem is, I try to rotate the wiper knob approx. 50% where only the pump runs. It takes about 1-2 seconds to push the water through the nozzle. After that, I turn it completely so that the wiper can start working along with the washer.

[Ashtoncastelino]

Easy fix.

When I installed the rear wiper with washer in my Swift VXi , I purposely made sure I installed two check valves ( non return valve) near the washer reservoir in between the plumbing.

Attaching the boodmo link of the non return valve by Maruti. Hope this helps.

https://boodmo.com/catalog/part-joint-6799171/

Regards
Ashton Castelino

[vivekkp]

Originally Posted by scorpian

This behavior that you mention is common across many cars and is not to be worried about.

I wouldn't take this issue so lightly. Imagine an entire sweep being done by the wiper without any fluid. What if there are some small debris collected in the wiper blades and now when the sweep is done without any liquid, it will for sure leave scratch marks on the rear window in the long term to the extend that it could impact the rear visibility to the driver.

Mahindra has to fix this. Period.