- 1: Wiperblades "just stop" during operation and the only way to fix it is turn ignition off and on again, or wait several minutes.
- 2: Wiperblades are not stopping at the right point, often "parking" a couple of inches up the screen, but reset when you turn car off.
Then this is the HowTo for you!
(and even if you don't have these issues, it's probably good to do this when you have a free half-hour, to save you from experiencing it at 70 on the M1 in a downpour!)
1x Non-new shape BMW Z4 (Well, it may work, but the instructions are bound to be slightly wrong!)
1x 15mm socket and driver (or spanner)
1x 8mm Allen key or socket
1x Torx 30 screwdriver or socket
1x Torx 20 screwdriver or socket
1x Small flathead screwdriver
1x Can of penetrating / easing oil (WD40 will do perfectly)
1x dry cloth / bogroll
1x Rubber mallet (optional, but may be useful)
Open the bonnet and remove the black plastic covers for the windscreen wiper arms (they just pull off):
Using the 15mm socket, undo the arm retaining bolts.
Once removed, spray a generous amount of the easing oil onto the bolt the arm is attached to (it can be damn hard to shift them if they've never come off!)
Holding onto each wiper arm about 6 inches from the mounting bolt, gently lift the arm upwards (not like you would to change the blade, but try and actually tilt the arm against the bolt.):
As you do this, you should feel the arm come loose from the bolt. At this point, you can lift it straight off the bolt.
If it doesn't want to budge (mine didn't at first), a gentle tap with a rubber mallet on the bolt freed it for me.
IMPORTANT: Save yourself fifteen minutes of swearing, by placing the wipers in a safe place, remembering which one came from the left and which was from the right... as they're slightly diffrent sizes
Also, mark their resting position on your windscreen with a bit of tape, to avoid problems re-mounting them.
lift up the rubber seal that runs around the edge of the wiper pan. You only need to lift the first two inches of the rubber from either end, not remove the whole thing!
Using the allen key, undo all four bolts that hold the lid onto the fuse box. (these bolts stay in the lid - they don't fully unscrew!
Remove the fuse box lid by lifting the left edge nearly vertical, before pulling it out from the clips.
Using your flathead screwdriver, remove the four plastic screws that hold the wiper pan cover in place.
These screws are rather crap and although they have a posidrive slot, I found the posidrive screwdriver just churned them up.
Using the flathead, you can "push into" the plastic and maintain a good "grip" on the screw as you undo it.
As you undo it, A: don't drop the screw into the engine bay - you'll not find it, and B: prise out the plastic grommet thingy that it screwed into, again making sure not to drop it into the engine bay!
These are really crud screws. I managed to destroy one and another member experienced the same. Try and maintain pressure against it as you unscrew, else you're likely to slip and churn the head completely :'(
Unclip the conduit shown in the following picture. If you also have an alarm, the bonnet
pressure switch loom will be clipped in here too:
With all four screws removed, you should be able to remove the wiper pan cover.
It is attached to the windscreen edge by approximately 8 press-fit clips. Whilst lifting the lid, be careful not to snap these.
(I lost 4 , but it still fits perfectly with no issues, but if I knew about them before lifting, I'd have done it more gentle!)
With the cover now removed, you need to unscrew the two Torx 30 bolts that hold the motor assembly in place
At the centre of the motor assembly, you'll find a small white plastic clip that holds the motor in place.
Insert your flat head screwdriver into the small slot on the right side of the clip:
Then bend the screwdriver to the left, which should force the clip free and allow you to open it and thus remove the motor assembly:
With the two bolts and clip undone, you can wiggle the motor assembly clear of its mountings and undo the electrical connector from behind.
Turn the assembly over and you should find six Torx 20 bolts that hold the backplate onto the motor.
Undo these and then gently lift the back cover from the motor.
Be very carefull when doing this, as there is a paper gasket between the lid and main housing.
Also, there are pins that extend from the lid into a socket in the housing, so you must lift the lid vertically - don't twist it!
With the lid now removed, you should see something like this:
Using your soft rag / bog roll, remove ALL traces of the grease and gunk that has built up on the white plastic in the big gap (circled in red)
It is this grease that is causing the problem. Basically, it creates a conducting path across the points, confusing the motor operation.
It looks like it's made it's way out from the worm gear. I removed ALL of the grease I found on the copper plate and surrounding plastics, as I
could see no reason for it to be there.. so far I've had zero problems.
Re-assemble everything in the reverse order
And that's it.
As I say, I've done this to mine, after being told by the dealer it'll cost me a whole new motor assembly, and it's fixed both of my wiper issues.
Since doing it, I've had ZERO issues with the wipers
Hope it helps you!