Wiper Chatter

The "intermittent" wipers do not have an interval. There is a sensor on the windshield behind the rearview window that detects rain so "in a really heavy downpour, they speed up all on their own."

This is one of my favorite features on my Bimmers...living here in Vancouver we have many different types of rain and it changes all the time. In our minivan I'm constantly adjusting the intermittent wiper setting. In the Bimmers it just lets me focus on driving.

Did you read the manual? There is a sensor for the intermittent wiper control. That's the whole point...as the volume of water increases, wiper speed increases accordingly. I just had mine dialed back a bit because they were hyperactive overall.

Originally Posted by PPXYZ

I did not like the original BMW wipers but they seem to have settled in and are fine now after more than a year of use. What I do not understand is the timing of the wipers. The intermittent setting appears to be completely random and, in a really heavy downpour, they speed up all on their own.

That's the rain sensing wiper system in action. It's not a fixed time interval that's driving the wiper swipes (as in a traditional intermittent wiper system); there's a sensor in the upper part of the windshield (part of the rear view mirror mounting assembly) that detects the intensity of the rain and swipes the wipers accordingly.

Originally Posted by Supercourse

Yes. When X3 was new, I was plagued with juddering wipers - gave up on the O.E. refills and went to these:

http://www.autobarn.net/piwiblre.html

Never had the problem since (over 3 years).
They last much, much longer, and perform really well.
These refills fit in the X3's wiper blades perfectly (they don't fit all types of blades).

I'd be wary of using Bosch Icons on the X3.
You would lose your anti-lift aerofoil on the driver side.
From most accounts they might look great, and work well enough initially, but they don't last too long, and they are throwaways.

+1 on the PIAA.

In the manual it says that the serrated dial is to 'select interval time or set sensitivity of the rain sensor.'

'you can set the wipe interval to four stages with the serrated dial 5. In addition, the wipe interval is varied automatically depending on road speed.'

The road speed seems to work sometimes and not so other times. I do not have the rain sensor which means I have the intermittent function which does appear to operate oddly.

If you have the rain sensor, the serrated dial 5 adjusts sensitivity.

Since the intermittent function doesn't work. I will accept the rain sensor explanation.

The dealer tried to tell me, as if I didn't speak nor understand the value of a Wiper blade, that it will cost $200.00 to replace the blades, because "we replace the motor and arms as well..." REALLY!? Ingot my replacements from www.Rockauto.com
Try them.

I had a reall bad chattering problem on my wife's X3 and tried most of the suggestions to no avail. What I found when I took the system apart was that the bolts that hold the wiper stems to the firewall were slightly loose. These are not the nuts that hold the wiper arms to the wiper stems - you have to remove the wipers and the spacers to get to them.

After tightening them down & reassembly, everything worked great. I don't know if I had a typical situation or something special, but this could be the root cause of a lot of the problems. It stands to reason that if that connection is not tight, you would get a lot of chatter, but if you do things to reduce the friction between the blade and the windshield, that would reduce the symptoms while not attacking the root cause.