Rear window won't close
 

Though I have managed to get it up now, there's something very wrong.

Driving along hear a "funny noise" from the nearside behind me, thought it might be the nearside rear window a bit open so I tried to close it. Nothing happened, so I tried opening it a bit.
Upshot was, it kept opening more and more but wouldn't close, combined with some disturbing noises.

Eventually found a safe place to park and managed to force it up using hands on the glass and operating the switch. Kept hearing graunching noises as if something (glass maybe ) was caught in the mechanism.
Only got it up in tiny steps, the auto-reverse mechanism kept kicking in. Where are the sensors for that, it might give me a clue?

Any thoughts anyone, I guess the door will need to be stripped to investigate but how difficult is that?

I need to use the car again today so won't be investigating until later in the week. Might scupper plans to go to Audis In The Park on Sunday.

That sounds exactly like my rear door when I went to the Annual Meet!
I only managed to get the window partly closed. So I taped the opening in case of rain.
Stripping the door isn't very difficult. But the wire going to the lock was difficult to fit again, in my case.

In my case it was the wire that had broken off.
http://forum.a8parts.co.uk/showthread.php?t=14232

Johannes I think mine is subtly different. There is motor drive both up and down and the window WILL close, but when it starts moving up the anti-trap mechanism starts lowering it again.

It's quite likely that something is broken or adrift (or debris from somewhere) but I suspect that is fouling the mechanism causing it to reverse automatically.

Thanks for the link to your thread, a useful reminder of how to start taking it apart. I've done front doors, so hopefully the rear is easier.

Andrew, instructions on how to remove the rear door cards can be found here:

http://forum.a8parts.co.uk/showthrea...5205#post85205

My A6 passenger window does exactly the same. I think the cable is frayed so its happy to go one way but not the other. It usually has to go all the way down before it can be persuaded to go up again.

Thanks Sean and MJ, I may investigate tomorrow.
As the motor drives it both ways I'll probably try some silicone lubricant in the glass channels first.

Can anyone comment on my question re the safety back-off which it is doing? Where are the sensors for this?

Its in the motor - it detects the current load and if its too high it reverses.

Thanks. So that's why I can inch it up in small stages while applying upward pressure on the glass. +++

Finding the cause of the obstruction will be the task, unless it's an actual faulty motor.
Given the unpleasant noises I've heard it does sound like a mechanical obstruction somewhere.

Edit: MJ beat me to it!

I suspect there are no sensors as such. I can't be certain, because I've no knowledge of how the D2 electric windows work. But, from an electronics design point of view, the most common method is to use current sensing to detect an obstruction. Current sensing may also explain the need for the controllers to 're-learn' (by holding the switch to fully open/close the windows) whenever the battery has been disconnected.

I've not had a D2 window mechanism fail on me (yet) but it would appear they operate in pretty much the same way as my old Citroen XM windows used to do (essentially a steel wire rope and pulleys) and on the XM they would fail alarmingly frequently. Audi window mechanisms are clearly better designed/built, since they last longer, but ultimately they will no doubt be prone to the same type of failure ... a rusty rope. My guess, I'm afraid to say, would be that it's not an 'obstruction' but a frayed rope. My XM windows often behaved the same way, shortly before the rope snapped or jammed. :(

Rereading your original post again, and what others have said about how it detects an obstruction, it sounds like the steel cable used in the mechanism has started fraying and wrapping itself around the motor spindle. That will add to the pressure on the motor itself, and hence it thinking there is an obstruction, and backing off.

If you look at the last picture Johannes posted on the thread he linked to, showing the window mechanism, I suspect you'll find quite a bit of the cable around the yellow spindle.

Thanks Sean, I'll investigate with the door card off sometime soon. :cool:

Just had a little "play" and I can eventually get it back up (with graunching noises and hand pressure on the glass) so I'm going to leave it until after Audis In The Park (this Sunday) and take the risk on the day.
Not definitely going anyway as I'm a bit crock at present (another reason to leave it) and the weather forecast was somewhat damp last time I looked!

Similar situation
 

Here's my post from when my rear window started developing similar symptoms to the one you described.

http://forum.a8parts.co.uk/showthread.php?t=10221

Cheers
JWG

So the D2 Doctor doesn't do A6's?

I'm postponing doing mine as it's booked in for an MOT this coming week, then I'm too busy for couple of weeks to even investigate.

I might be heading down your way MJ, if the D2 Doctor has availability in September....

Had exactly that in my Infiniti - window wound down happily but getting it back up would be accompanied by all manner of crunching

One strand of the wire rope had snapped and was getting mangled at the first pinch point in the system - in my case one of the lower pulleys.

Given the lack of Infiniti parts in the UK (just about everything is 4 weeks from Japan) I had to strip the mechanism out of the car and remove the mangled wire.
Stripped it back to where I could tape up the frayed wire without running through any gearbox/pulleys and reassembled -worked for months before I got round to swapping over with a new regulator unit.

I never get time to fix my own stuff :rolleyes:

I'm doing triage sessions in September so lmk when you'll be passing and we'll sort something out +++

Today I decided to finally have a look at this errant door. And I've found the problem.
Despite having had door cards off before it didn't go too well. :-(

Managed to break a lug on the lower part of the door pull when taking it off, despite having done this several times before.
Broke, as expected, almost every fixing clip on the trim panel - boy were they in tight!
Found an unexpected layer of black stuff held by mushroom-style clips, plus evidence (tears in it and duct tape) that someone had been in there before. :tuttut:
No obvious way to disconnect the wiring loom without going to every individual component so left it connected.

Nearly lost the little black thing on the door handle Bowden cable! And stressed the plastic moulding that it clips into as it popped out before I could disconnect it properly.
Finally got to the window motor and its Bowden cable, which all seemed fine as far as I could reach with my big hands.

But in the bottom of the door was this, so I presume a pulley higher up has shattered. I'll be on the phone to A8parts in the morning:

The way the doors are put together on the D2 is just a clusterfcuk of stupid ideas and this is one of the worst offenders! The A4 and A6 have a nice set of connectors clipped to the door card so they all just come apart and you can take the card off completely.

Don't lose the little black thing - they are NLA!

It's safe in a sealed plastic bag now. :cool:

I'm sure I read somewhere that it's actually easier to replace a whole chunk of frame with the motor etc. attached. Any comments anyone?

All closed up now, but it looked like there was a serious metal plate this was all mounted on that was held to the rest of the door by 4 big bolts.

Yeah it is easier to replace the whole frame complete with mechanism as the cable assembly is riveted to the door frame.

Indeed it is riveted to the door.
Here is a better photo of the whole mechanism for the right rear door

Thanks Johannes. It's presumably that big white pulley that has broken.

When I come to swap the frame over do I start with the window glass up or down or in between? At the moment I can move it so I'll get it to the best position before starting work (though that won't be for a few days).

I presume it's necessary to remove the frame first, then take the glass off it, fit to the new frame and refit everything.
Sounds so simple...……..
(Must remember to get a load of clips for refixing the trim, hopefully A8parts will have some)

I am actually not sure what position will be better.
I removed and refitted it with the window closed, and that made the whole frame easy to handle.
You can connect the wires while the frame is off and lower/raise the window.
Have a look at these photos and see what you think?

That is correct

Thanks Johannes. +++

How does the glass come out, is it just one bolt securing that black support to the mechanism, then slide down?

Yes there is only a plug with a clip, and one guide on each side in the window itself.
Mind the wire going to the door lock though. I struggled fitting that again.
Try to leave it in the door lock mechanism, and remove it in the end where you found the black thingie :)

Edit: Lower the window fully and remove half the holder in the bottom, to get the window out. The holder is 2-parts, one on the inside, and one on the outside. Then wiggle the glass out

When the frame is fitted to the door again. You will probably have to adjust the window a bit to get it to close properly. Adjust it in the bottom where the black support is :)

Thanks Johannes, presumably it's easier to do that adjustment before fitting the frame back on the door?

Just had a nice chat to Maria at A8Parts and ordered the necessary, plus a couple of little items I've been thinking of for a while.
Too big for overnight delivery so should arrive Monday, at least my weekend will NOT be spent working on the S8. :ROFL:

I would believe it is easier to adjust with the frame back on the door.

Maria at 8parts is great :)
I am in the process of ordering some items as well, from a breaker here in Sweden. But they do not have all the parts I need. So I will be making an order from 8parts as well, looks like

Or maybe it will. :Confused:
Definitely shipped as a "48-hour Large" item and collected yesterday.
BUT it's made it to my local depot overnight and is now out for delivery, expected about 2pm this afternoon. :eek:

Edit: Arrived safely. :cool: Courier was very surprised how light it was when I explained it was a large section of a car door, made of aluminium.

Dont forget to lubricate the runner slots as well as the window channels Andrew, makes a huge difference to window load/speed

Anything specific you'd recommend for that?

Window channel lubricant
 

When I had the pleasure of replacing the whole rear passenger window frame (which was basically the top half of the door frame), I used a can of silicone spray from Harry Halfords. Seemed to do the trick at the time.

I'm sure the lack of lubricant plus the fact that my snapped cable was a tad rusty was the cause of the original failure. I tend to to spray all window runners/frames/guides on a 2-3 month basis, but to be honest I do it whenever I remember.

I haven't even thought of this. It is an advice I will take to heart as well

I use a PTFE style dry lube (spray can preferably, stick too fiddly).
Silicone spray is also good

You're after a lube that wont gather dirt.


Got a mate who uses lithium, but I think it's too grease like and attracts dirt. I use lithium on the sunroof and bonnet/boot hinges.

Good progress today, no useful photos though, but a few quick notes:

Disconnected the motor easily - three Torx bolts (T10?) and a wiggle and it's off. You can then move the window up and down more easily (though not so easy with a broken pulley...)
Also need to unhook the locking button cable; unclip from it's guides and move the end round and out it pops. And peel the door seal off the outer door panel at the rear edge.

Four big bolts to free the frame; couple of shims in the lower ones - a sizeable (semi-captive) wedge at the front and a thin one at the rear.
These obviously relate to the final fit and shut lines, I didn't need the thin one with the replacement.

Lift it up to free a locating peg at the front, wiggle out the interior handle and locking cables and it's off. My shims both fell out as expected.
Note the rather tortuous route of the interior handle cable via a narrow slot, it needs care when reassembling!

There's a small piece of rubber trim blocking the front (longer) window channel that only comes off easily with the glass right up. Remove it then lower the window.
Prise off retaining clip, lift window bracket off the pin and wiggle it down until it's off. A couple of little guide pieces fall out of the channels, they go on the end of the guide pegs.

While the glass is out transfer the rear blind hooks if necessary (it was for me).

Move window to replacement frame and refit, not forgetting the little white guide pieces in the channels and to lubricate first! I found it worked best to push the window tight shut before fitting the retaining clip at the bottom. It was then a good fit when all was reassembled. And when shut refit the rubber trim at the bottom of the channel.

Fit the frame back on the door, remembering to put the handle/lock cables in the right place and keep an eye on them as you lower it down in stages.

Fit the top (shorter) bolts first and don't do up too tight. Then the lower (longer) bolts and shims as required. Test fit to the door opening and adjust by moving the bottom in and out.

Refit the motor and test. NOTE: You need to connect the rear door window switch to do this! The drivers door controls will not operate that window without it.

I then reconnected the locking button and checked that the door locked OK and that global window close was also OK.

That's as far as I got today; refitting the door card and interior handle can wait for another day as the car is now secure and the main problem fixed. +++
I also intended to swap the rubber door seal over as the black shiny triangle is part of that and mine was in excellent condition, the replacement has a few marks.
Sadly that just seemed a bit too difficult so I didn't bother. I'll investigate another time; it may be possible to just take the triangle out and swap it, or more likely repair/repaint it.

The attached picture is the frame after I removed it from the car with glass still attached. You can just see that the top pulley is only the metal centre, missing it's outer nylon disc!

I wonder if those pulleys could be printed...?

I doubt it, they need to be pretty strong, especially the upper one!

And it's all riveted so replacing them isn't trivial.

I don't really understand why it's not metal, unless it's for noise reduction?

And it isn't, it's moulded into the rather complex rubber seal, so I'll live with what I have for now.

Job finished but took a fair bit longer to fit the door card than expected.
When I came to investigate the clips etc. I noticed they were a mixture, some were the correct type (of which a couple broke) and the rest were a different design which didn't hold anything like as well, but were largely reusable.

So, someone had been in there before, and not used the right components. :tuttut:

A quick scout round found various bits disturbed, non-OEM wiring joins, duct tape in strange places and a strange label! :eek:
This label had some vaguely D2-related codes (but not valid part numbers) starting 4D0 899. It also had the magic word "NOKIA".
So something was once in there related to a mobile phone. Nearside rear door is a bit odd though...

Nothing surplus now, apart from duct tape and the label, but some foam bits were loose so I tidied it all up.

Final footnote. The repaired window is now the fastest to open and close. :cool:

Nice work. +++ You'll no doubt be rushing to (preventively) fix the rest of the windows now so that they all open and close at the same speed :D

I wonder how easy it would be to make a mold of the plastic pulley and cast a new one from aluminium.

Probably easier to do on a lathe, turn from a solid lump.

I'm going to look at my old one sometime and see what's involved in repairing it.
I doubt the exact size of the pulley is critical as long as it fits, it's just passive to take the cable round a corner.