e39 wipers operate oddly when in interval mode

[Arma 134]

When I put wipers in interval mode (whatever it is called - the first mode, where it is supposed to wipe every set interval), it behaves very oddly. Sometimes it will be raining down a lot, and it just does not wipe the windscreen at all, and sometimes it wipes the windscreen in odd intervals e.g. wipe, wait 1 second, wipe, wait 5 seconds, wipe, wait 2 seconds - and it sometimes waits only 1 second when there is almost no rain, and waits 5 seconds when it is raining a lot. Not sure what the issue is - not a huge deal as the next two wiper modes work fine, but was just wondering what might cause this, or if it is for some odd reason suppose to behave like this . This is in the 2001 530i.

Edited May 30, 2013 by Arma

[RustyItalian 11]

Is the sensor still firmly attached to the inside of the screen? I've seen one fall off before.

[Tristan 338]

Two suggestions:

a) Sensor against the windshield behind the rear-view mirror may have fallen

B.) There are different speed settings on a "sliding dial" on the windscreen stalk

Edited May 30, 2013 by Tristan

[Arma 134]

Two suggestions:

a) Sensor against the windshield behind the rear-view mirror may have fallen

B.) There are different speed settings on a "sliding dial" on the windscreen stalk

Unlikely option B, because no matter what the setting on the sliding dial, it still behaves oddly. Think it might be something up with the sensor (e.g. has fallen); will check tomorrow. Gotta get that front right tire changed finally - seems to have gone almost flat somehow, noticed when driving back home

[NZ BMW 368]

You've got them set to rain sensor - my understanding (and it's certainly true in my case) is that the sensor, despite being firmly attached is not really that great. They work most of the time, however on occasion it does get confused and takes a bit longer to wipe in heavy rain or wants to wipe at a shorter interval in light rain.

[M5V8 337]

mines abit hit and miss also. I use it infrequently as I find i always am over riding it to wipe more or less.

[yng_750 247]

yea sounds like a faulty sensor, very common to play up after windscreen replacement, my e39 has a sensor but seems to sit on a set interval regardless of the rain.

dial is meant to set sensitivity.