[Kilgour]

Not my first bimmer but definitely my first issue with Rain-X vs. BMW. My 2-month old G20 needed windshield washer refilling for the first time; I picked up a jug of Rain-X washer fluid, filled it up, good to go. But apparently not. Noticed the ‘low washer fluid’ indicator was still sounding. Figured maybe it was an air-lock. Nope. Searched it up and ‘lo, for the first time ever I learned, the hard way that washer fluid with silicon additives (Rain-X) does NOT cooperate with our fluid reservoir sensors. I’m hoping I can just empty the tank and flush it, and hopefully the sensors will come back to life. I guess I could just run my wipers until I run out of fluid (an entire gallon), but I don’t want to clog anything else up - like the wiper nozzles themselves. Has anyone siphoned the washer-tank empty on a G20? I figure there’s likely a screen partway down that may block the hose, even a hose even fits. I’m in a condo and have access to very few tools. If a bucket and a hose will work, I can do that - but I’m curious if anyone has been through this already? Any suggestions? Thank you!

[Jer025]

Originally Posted by Kilgour

Not my first bimmer but definitely my first issue with Rain-X vs. BMW. My 2-month old G20 needed windshield washer refilling for the first time; I picked up a jug of Rain-X washer fluid, filled it up, good to go. But apparently not. Noticed the 'low washer fluid' indicator was still sounding. Figured maybe it was an air-lock. Nope. Searched it up and 'lo, for the first time ever I learned, the hard way that washer fluid with silicon additives (Rain-X) does NOT cooperate with our fluid reservoir sensors. I'm hoping I can just empty the tank and flush it, and hopefully the sensors will come back to life. I guess I could just run my wipers until I run out of fluid (an entire gallon), but I don't want to clog anything else up - like the wiper nozzles themselves. Has anyone siphoned the washer-tank empty on a G20? I figure there's likely a screen partway down that may block the hose, even a hose even fits. I'm in a condo and have access to very few tools. If a bucket and a hose will work, I can do that - but I'm curious if anyone has been through this already? Any suggestions? Thank you!

Maybe syphon as much as you can and fill back up with regular fluid to get a good mixture. I doubt you will clog the nozzles.

[A6bullet]

Originally Posted by Kilgour

Not my first bimmer but definitely my first issue with Rain-X vs. BMW. My 2-month old G20 needed windshield washer refilling for the first time; I picked up a jug of Rain-X washer fluid, filled it up, good to go. But apparently not. Noticed the ‘low washer fluid’ indicator was still sounding. Figured maybe it was an air-lock. Nope. Searched it up and ‘lo, for the first time ever I learned, the hard way that washer fluid with silicon additives (Rain-X) does NOT cooperate with our fluid reservoir sensors. I’m hoping I can just empty the tank and flush it, and hopefully the sensors will come back to life. I guess I could just run my wipers until I run out of fluid (an entire gallon), but I don’t want to clog anything else up - like the wiper nozzles themselves. Has anyone siphoned the washer-tank empty on a G20? I figure there’s likely a screen partway down that may block the hose, even a hose even fits. I’m in a condo and have access to very few tools. If a bucket and a hose will work, I can do that - but I’m curious if anyone has been through this already? Any suggestions? Thank you!

It shouldnt clog anything but I think syphoning it out would be the best bet. Mix it with water or a regular fluid.
However, I think I heard the sensor might be permanently damaged, but im not sure if thats true.

Let us know how it goes, good luck.

[WXdrivefun]

There's a maintenance section here on the forums here about windshield fluid and Rain X... even for past BMW's forums as well when googling

https://g20.bimmerpost.com/forums/sh....php?t=1647341

[NorCalAthlete]

Might be similar to the AR vs AK gun debate - AKs are notoriously "will run anything you throw at it" largely due to looser tolerances in manufacturing + overpressure gassing.

BMWs are more precise / refined / whatever, meaning you have to be more careful with everything.

I dunno just a theory, it seems weird to me that RainX clogs anything or screws up anything internally.

[Kilgour]

Good News! This kid finally finished the Rain X, and filled up with BMW washer fluid (it’s purple). Immediately the ‘low fluid’ indicator was resolved. My rep had never heard of this issue, but the parts manager had.

[VipinLJ]

I've stayed away from RainX after reading about it messing up the sensor, especially in BMWs. I've used the cheap stuff from Walmart and gas stations in my Audis and BMWs for years and I've had absolutely no issues till date.

[CrownRoyal79]

I leased a 435i and used nothing but RainX in it for 3 years and never had a problem. In the G20, just to play it safe, I use a 50/50 mix of RainX and BMW fluid. It works great. I still get the beading effect on the windshield when it rains.