Howto: Fix Problomatic Wipers

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sk93

Lifer
If you've got either of the following problems:
  1. 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!)


Requirements
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)

Costs
Zero

Step 1
Open the bonnet and remove the black plastic covers for the windscreen wiper arms (they just pull off):
IMG_0003.JPG


Step 2
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!)

Step 3
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.):

IMG_0006.JPG


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 :P
Also, mark their resting position on your windscreen with a bit of tape, to avoid problems re-mounting them.

Step 4
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!
IMG_0007.JPG


Step 5
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!
IMG_0012.JPG


Step 6
Remove the fuse box lid by lifting the left edge nearly vertical, before pulling it out from the clips.

Step 7
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 :'(

Screw 1
IMG_0008.JPG


Screw 2
IMG_0009.JPG


Screw 3
IMG_0010.JPG


Screw 4
IMG_0013.JPG


Step 8
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:
IMG_0010.JPG


Step 9
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 :headbang:, but it still fits perfectly with no issues, but if I knew about them before lifting, I'd have done it more gentle!)
IMG_0016.JPG


Step 10
With the cover now removed, you need to unscrew the two Torx 30 bolts that hold the motor assembly in place
IMG_0017.JPG


Step 11
At the centre of the motor assembly, you'll find a small white plastic clip that holds the motor in place.
IMG_0019.JPG


Insert your flat head screwdriver into the small slot on the right side of the clip:
IMG_0020.JPG


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:
IMG_0021.JPG


Step 12
With the two bolts and clip undone, you can wiggle the motor assembly clear of its mountings and undo the electrical connector from behind.
IMG_0022.JPG


Step 13
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.
IMG_0023.JPG


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!

Step 14
With the lid now removed, you should see something like this:
motor_grease.jpg


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)
IMG_0025.jpg

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.

Step 15
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!
 
oh yeah.. whilst you're doing this, it's a good opertunity to remove the small amount of rainforest you'll find in there.
You can also clean out the drainage holes for this compartment too while you're at it :D
 
Once again, excellent job, sk93!

Will be giving this ago myself as soon as I get a moment. I bet a draw blood and cause the lady next door to close her windows so her children don't learn any of my favorite swears!
 
I managed not to cut myself doing this (which is a rarity - I can cut myself washing the thing!), so you should be ok :)

Only annoying bit is removing the wiper arms, as they're damn tough. Just persevere with the oil and don't get overexcited with the mallet - needs to be a gentle TAP, not a smack. Lots of wiggling on the arm also seemed to help :)


Whilst doing it, if you can take a photo of your grease build up and post it here, that would be really good.
I wouldv'e done it, but I needed to do this on the side of a road the first time.
This time It was in the garden, with a camera, but obviously no grease!

Good luck :)
 
Done!

My issue was with the intermittent setting - the wipers either didn't start or park correctly.

sk93 - the pic you wanted...
motor_grease.jpg


A couple of points I noticed...
1. Step 5 for me used a Torx 20
2. I doubt anyone would miss it, but I needed to remove the conduit hose in the Step 7 - Screw 3 pic.
3. Take care selecting a flathead screwdriver for the screws in Step 7, the plastic screw heads are very soft! In addition to the one a predecessor had rounded off I managed to ruin another!

I would re-itterate, the removal in Step 8 - what a PITA! I very carefully prised away the wiper pan starting at the outside, very gently pulling up until I heard a click before moving on to the next section. Even with great care I snapped some of the retaining brackets, if anyone knows a method please speak up!

One last tip I might add.... before taking off the wipers I would mark their position on the windscreen using masking tape - I spent far too long deliberating over their correct position!

Thanks again, any issues were due to shortcomings on my part - the instructions are sound. :thumbsup:
 
sk93 - an excellent post - it's what makes this Forum so good when people take their time to share such information with a good write up and pics to boot - MANY THANKS! :thumbsup:
 
I did this a little while ago. Thanks for the guide! :)

Does anyone have a picture of their wipers in the parked position. I get the feeling mine are a little high but could be normal?
 
PawnSacrifice said:
A couple of points I noticed...
1. Step 5 for me used a Torx 20
Double-checked mine, and they're definately 8mm allen key for me - must be slightly different for different models :/

PawnSacrifice said:
2. I doubt anyone would miss it, but I needed to remove the conduit hose in the Step 7 - Screw 3 pic.
Added an extra step for this - cheers!

PawnSacrifice said:
3. Take care selecting a flathead screwdriver for the screws in Step 7, the plastic screw heads are very soft! In addition to the one a predecessor had rounded off I managed to ruin another!
Put an extra warning in for this - if it makes you feel better, I rounded off one and lost another in the engine bay :'(

PawnSacrifice said:
I would re-itterate, the removal in Step 8 - what a PITA! I very carefully prised away the wiper pan starting at the outside, very gently pulling up until I heard a click before moving on to the next section. Even with great care I snapped some of the retaining brackets, if anyone knows a method please speak up!
Talking to BMW servicing, this is the correct way of removing it.. crud design imo.

PawnSacrifice said:
One last tip I might add.... before taking off the wipers I would mark their position on the windscreen using masking tape - I spent far too long deliberating over their correct position!
I'll add it to the notes, but I just dropped them on so the wipers tied up with the muckmark on the window.. guess it does pay to have a dirty car :P

PawnSacrifice said:
Thanks again, any issues were due to shortcomings on my part - the instructions are sound. :thumbsup:

My pleasure :D glad you got through it and I'm glad it worked (mostly) for you!
 
AlanJ said:
sk93 - an excellent post - it's what makes this Forum so good when people take their time to share such information with a good write up and pics to boot - MANY THANKS! :thumbsup:

Its a pleasure.. already got a fair deal from this site myself, so it's good to give back when you can :)
 
Richard! said:
I did this a little while ago. Thanks for the guide! :)

Does anyone have a picture of their wipers in the parked position. I get the feeling mine are a little high but could be normal?

here yah go.. they sit pretty much at the "line" between the black windscreen border and the clear glass.
Not saying this is the right resting point, but looks right to me :)
IMG_0027.JPG
 
in my unprofessional oppinion, they look fine :)
mine were sitting about level with the top of the tax disc when they were knackered ;)
 
Just finished and they seem to be fine. I'll see tomorrow morning while driving down the M1 if they are fixed.
Yes, you're right the 4 plastic screw are made of chocolate and strip very easily, I borke a head of one and had to remove the torsion bar across the engine so I could drill out the snapped head. I have a motorbike which I use on track so have loads of spare screws etc and an aliminium fairing screw was the same size. I replaced all four. You can get them from variuos bike dealers for a couple of quid.

My nut on the washer was a size 16 not a 15mm.

I gave the engine bay a quick wipe over as well as I don't think the previous owner even opend it, it was filthy and very dusty. Come summer I'll give it a proper clean.

Thanks to SK93 for a very good post.
 
shongololo said:
Just finished and they seem to be fine. I'll see tomorrow morning while driving down the M1 if they are fixed.
Yes, you're right the 4 plastic screw are made of chocolate and strip very easily, I borke a head of one and had to remove the torsion bar across the engine so I could drill out the snapped head. I have a motorbike which I use on track so have loads of spare screws etc and an aliminium fairing screw was the same size. I replaced all four. You can get them from variuos bike dealers for a couple of quid.

My nut on the washer was a size 16 not a 15mm.

I gave the engine bay a quick wipe over as well as I don't think the previous owner even opend it, it was filthy and very dusty. Come summer I'll give it a proper clean.

Thanks to SK93 for a very good post.

16mm eh? hmm.. I'll double-check mine incase I wrote it down wrong ;)

It's funny you mention the fairing screws, as that's exactly what I used as a replacement for mine... had a few kwak ones lying around, so just sanded off the paint and found they were black underneath.. very handy and look like the originals :P

glad it seems to working for you - and hope it is for tomorrow :)
 
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