Water in wiper motor - Bimmerfest - BMW Forums

Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

Please follow the links below to help get you started!

Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 5 Series > E39 (1997 - 2003)

E39 (1997 - 2003)
The BMW 5-Series (E39 chassis) was introduced in the United States as a 1997 model year car and lasted until the 2004 when the E60 chassis was released. The United States saw several variations including the 525i, 528i, 530i and 540i. -- View the E39 Wiki

Thread Tools Display Modes
Old 12-19-2011, 01:11 PM
rnadoc09 rnadoc09 is offline
Registered User
Location: North Carolina
Join Date: Dec 2011
Posts: 1
Mein Auto: 525iT 2003
Water in wiper motor

So, I thought I would share this. I've searched and only found a few references to this problem. My suspicion is that when someone takes their car to the dealer and they find the motor isn't functioning, they just chuck it and replace it. I doubt they actually take the motor apart and try to see if they can fix it. Maybe I'm wrong about that, but that is my impression.

Anyway, my wipers failed to work about 2 years ago and it was recommended by a BMW dealer to replace the motor. The car was under warranty and I paid only $50 to have this done. Unfortunately, they weren't too skilled and they didn't place the bushing under the left wiper arm. It happened to rain about 2 inches the next day and water got into the wiper motor compartment and found its way into my car. Literally had 3 inches of water under the front seat.

So, they fixed that (made them take everything out and clean to prevent mildew). Now, about 2 yrs later the motor fails again. So, knowing what I know about BMW dealers shops (at least mine) I decided to do it myself. I ended up testing the relay as other have suggested but this was not it. I ended up pulling out the motor and instead of throwing it out, I opened it up.

The component with the magnet was full of water...and rusty sludge. So I got a wire brush and knocked off the rust and cleaned it as best I could. I dried it out and put it back together and it worked! As I everything back together, I realized that water gets into the wiper motor compartment pretty easily. It seems to go in where the housing for the air filter (on the driver's side) sits flush with the cowl that covers the wiper compartment. I have taped over the edge of the cowl where it rests on the windshield to eliminate any chance of water entering that way. When the car is pointed up a hill, water simply pools in the cowl and then goes through the cracks and crevices where the filter unit lays flush to the cowl. I don't see any way to avoid this. It must do that in all E39s. If the car is pointed down hill, the water runs toward the front and there is an opening for it to run down behind the wheel.

Back to the motor. There is a tiny hole in the magnet housing. I assume that when water collects (maybe it was just that one storm back when they initially replaced the motor that caused a great accumulation of water and then soaked the motor) if it is deep enough, it will cover the hole. The rotation of the motor will then suck the water in. Eventually, rust ensues. The hole is so tiny, it would take forever for water to evaporate.

So, point is, when most people notice their wipers have failed, they'll check under the hood when it's dry out. Or the dealer will check inside. By then, any trace of water will probably be gone. Unless someone tips the motor around and water trickles out, they may never know WHY the motor failed. Thus, if the motor is replaced, it will likely fail again if the cause is water getting into the compartment. I would assume a good mechanic would test for water leakage when they put everything back together. Alas, I highly doubt that happens.

If someone is contemplating doing this on their own, here are some tips:

1. Tools - torque wrench, wiper puller or (works just as well and way cheaper) locking pliers, flat head and phillips screw drivers. You will need a hex screw driver and a tiny wrench as well. That's it.
2. Taking things apart is easy. Putting back together is not. The ducts for the heating/air system are the hardest part. Make sure you push from the base then rotate. You'll see what I mean.
3. If you take the motor out, when you replace it, you have to make sure the arms of the wiper frame (don't know the technical terms) are straight. That is, the linkage to the right and left wiper shafts have to be in line. If they at an angle, when you put it back together, the arms will not return to baseline. They will actually dip below the starting point and end above it. With the arms straight, the linkage is in the start position. To get the bolt on the shaft from the motor, you have to use a wrench because the wiper linkage is in the way at that point and you can't use a torque wrench. Make sense?
4. The plastic on the filter housings is easily broke. Be careful when removing then.

Points I'd like to pass along, then:

1. Wiper motor failure could be a sign of a bigger problem -- water getting into the wiper compartment. If that isn't addressed, a replacement motor is doomed to fail.
2. A waterlogged wiper motor can be salvaged with a little cleaning. As of right now, these motors are running around $400. It's worth the 30 minutes to take it apart and make sure it isn't something that can be fixed.
3. This is an easy do it yourself job. When it comes to reassembling the car, you really can only trust yourself. The dealer will try to throw things together as quickly as possible. They may leave screws out. They may not align things correctly. This could lead to problems down the road.
Reply With Quote
Old 02-15-2012, 10:14 PM
ztitans1 ztitans1 is offline
Registered User
Location: Texas
Join Date: Apr 2011
Posts: 69
Mein Auto: 1997 528
I wish this one had photos. I appreciate the write up because it is probably the same problem I have, but I still do not know how to access the motor. Does anyone have a DIY with pictures that show how to get to the part to check it? I have purchased relays and no luck. I suspect my motor may be misaligned with the linkages and not be returning the wipers to the proper parked position.

I just love this logo...
Reply With Quote

See More Related BMW Stories

e39, motor, water, wiper

Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 5 Series > E39 (1997 - 2003)
Today's Posts Search
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump

All times are GMT -7. The time now is 12:11 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
© 2001- VerticalScope Inc. All rights reserved.