How To Guide Z4 roof motor relocation to boot


Aug 3, 2019
Crazyone, there is no need to replace the motor, you are looking at £600 from BMW. Put your motor in a container of diesel overnight, in the morning squirt the brushes with wd40 or my favourite gt85, a few light taps with hammer to free the brushes and it will work when reconnected, if it doesn't tap it lightly when it is it at full tilt for a couple of mins to clean up the rotor and brushes.


Jan 11, 2020
I had to sign up just to say thanks to the original poster for the write up. My z4 succumbed to the dreaded dying roof but is now fully operational again. Saving me a shed load of £££.

Definitely not the easiest job in the world unless you have long arms and small hands but is actually quite straightforward.

I could pry the case out so used the drill a hole and Allen key trick to get enough purchase.

Thanks again!


Zorg Expert (II)
British Zeds
Dec 31, 2013
Torksey Lock,Lincoln, England
Model of Z
Z4 3.0 Auto
Hi Ralph, welcome from me near Lincoln. Congrats on getting the roof motor done, one of the most regular ailments of the E85. Where are you located please? Oh, and please show us some pictures of your car, we all like pictures.:)



Jan 11, 2020
I’m just outside Andover. Have put an intro thread up! I’ll have to dig out some pics as well...

Paul Milligan

Jul 11, 2020
Well, my missus's Z4 succumbed to the renowned roof motor failure last week.
Windows drop, roof unlatches then nothing.
So I set about a repair and decided to photograph what I did to get it, not only working, but relocated as well.

The main problem with the Z4 roof motor is its location.

The motor, surrounded by some sound proofing foam, sits in its own small black plastic housing,
This housing is tie-wrapped into a plastic moulded compartment just behind the L/H door (UK passenger side)
There is a drain hole in the bottom of the compartment, which can become blocked. The compartment will eventually fill with water, from rain and/or washing. and the water then spills into the motor housing.

The problem is this.

Imagine you have a bucket with a drain hole, (that is the plastic compartment behind the door).
Put a cup inside your nice dry bucket, (the cup is the motor housing)
Now put a motor into the cup
If you now plug the drain hole and start filling the bucket with water, eventually the level reaches the top of the cup, and the cup also fills with water.
Now unblock your drain hole and the bucket empties, but the cup does not.

No amount of further unblocking and keeping the drain hole clear will empty the cup, and that is exactly what happens to the Z4 motor, as it sits and slowly rusts away whilst remaining submerged. And it only has to fill once.

So here is the (second) way I did it: (other methods are available.... =)))
I know! I removed a roof once to do this on a previous Z4.

First job is to remove the parcel shelf.
To do this, squeeze together and push upwards the plastic clips. There are two on each side of the parcel shelf:

View attachment 111665

The clips will probably fall down the sides, but you can get them later,

Pull the fabric flap off the shelf:
View attachment 110183

View attachment 110235

Now pull each hinge upper plate away from the parcel shelf towards the centre of the boot:
this is best done with the parcel shelf in the upper position
View attachment 110187

Remove the parcel shelf by moving it towards the drivers side as far as it can go, and pulling the other end out. Then you can rescue any clips that you pinged off earlier.

Now you can remove the complete LHS hinge assembly for the parcel shelf.
Remove the Torx bolt at the front, and the bolt at the back.
View attachment 110189

View attachment 110191

There is also a rivet, in the now viewable plastic well.
Pull the centre of the rivet out with some pliers, and then remove the outer washer:
View attachment 110195

Now give the whole hinge assembly a good pull towards the middle of the car to remove it. A little hump shape underneath it provides some resistance, but otherwise it just needs a bit of effort.

Now you can see all the way into the well and behind the door latch is the dreaded motor in its housing:

View attachment 110229

cut the tie wraps to release the hoses

View attachment 110197

By lying on my back in the boot with both arms above my head and through into the compartment I was able to wiggle the housing about.

It is held in place by two tie wraps around the ram which is nearest the door, and on the RHS of the housing. But I could not get it to shift. I even tried from the door end but that was worse and just wasted time taking off the plastic cover and speaker compartments behind the seat. None of that is needed by the way, Everything can be done from the boot.

So what I eventually ended up doing was separating the motor housing,
The housing comes in two parts (see later photo's). It is held together with some black fabric tape.
I was able to pick at the tape and pull a lot of it off. Then with a long bar I was able to separate the top of the housing from the tie wrapped bottom section exposing the pump.
View attachment 110199

From then on I could pull out the pump/motor assembly, and finally wrench the bottom of the housing out.

The motor was soaked and rusty,
and the bottom housing was full of the dirtiest water imaginable, that could run down my face as I tipped it up in the boot over myself.....!
View attachment 110201

With the motor pulled into the boot you can see the ram and associated hoses to it, Try not to pull too hard on these:
View attachment 110205

Now you can see (with a camera) the bottom of the plastic well and the drain hole. Note the rusty water tide mark:
View attachment 110209

The housing looks as follows, with the tiewraps on the plastic fin which breaks away eventually:
View attachment 110213
You can see the remainder of the fabric tape that I couldnt get too

and inside is the sound proofing which stays soaked:
View attachment 110215

You can separate the motor from the pump by removing 2 allen bolts, but do this with the pump downwards and break the joint nearest the motor or you will lose hydraulic oil (ask me how I know)
With a quick wipe down and wire brush, I then sprayed WD40 all over it and inside it. then connected to a 12v power supply and it immediately came back to life so I ran it in both directions whilst still oiling it.
Sorry no pictures for that.

After putting it back together and topping up with hydraulic jack oil through the little plug in the top of the pump. (check level with roof down) I was able to get the roof up and down fully with no noises,
To operate the roof you have to temporarily press in the parcelshelf position microswitch (i used a 12mm socket for that):

View attachment 111675

The hoses that now go to the motor have to be routed across the plastic well and below the hinge. This involved cutting the plastic away and securing as follows:
View attachment 110225

The hinge assembly had to have the same treatment before being refitted:
View attachment 111677

Then time to rebuild:
I pulled out the LHS carpet from the side of the boot to be able to locate the motor.
I tiewrapped the dried out soundproofing around the motor and tied it to a little connector block which is under the LHS side carpet:
Keeping the motor underneath and the pump uppermost:
View attachment 110231

Then just wrap the carpet back around,
View attachment 111679

refit the parcel shelf and fiddly clips, and finally the fabric flap.

and most importantly have a beer, knowing that it will no longer get wet, It is easy to get to, and top up if required.

Over 2 grand to fix from BMW,
I did it for free.
Thanks for the detailed procedures and step by step instructions.
I now have a working roof, having cleaned and oiled my motor. Extracted it yesterday. Ran a bit rough but an oil and overnight rest helped. Reinstalled in boot but putting back the parcel shelf has driven me to drink. lol. Main task done though. The manual override valve had also seized up so had to free that up too. As others have said BMW, why there?? Probably so they cn charge you a fortune to fix a waterlogged motor. Cheers. Paul


Sep 26, 2020
Thanks for all the info. Had a failed motor for top on my new 2006 Z4M roadster. Used your method, took 6 hrs but got it out via trunk ( upside down and contorted!) Only problem was cut 3 of 4 hoses. I can reconnect with a good quality splice but don’t know which hose goes to which of the 3 remaining terminals. I may be able to tell by length of the hoses that may match up. Sprayed heavily wth wd40 and working now. The motor casing was dry as I live in Hawaii and not much rain or road junk.Cut power also but I think I can reverse polarity if switch is backwards.
will relocate to trunk. I would recommend to anyone trying this to use a 12v Dremel and cut top off casing rather than tin snips! Maybe use a long sharp hacksaw blade to get to wire ties at left bottom of plastic “cup”. Thanks again, and if any advice on hose placement would be icing on the cake!


Sep 26, 2020
It's happening all the time with my photos now. I have stopped updating my journal now as there is no point. I also keep getting a message saying '404 access denied' to the forum. Wouldn't mind but it costs me to host pictures on Flikr for here and they don't show up reliably anymore


Regular Member
Sep 19, 2020
Anyone ever refurb the Pump side ? Since mine rusted out I have a mustang pump/motor in there now. But since I already bought an ebay motor, I figure ill get the original pump working and hook it up to the ebay motor as a spare.

I have read that there might be some valve issues or the bowden button issue, is that something a DIY can repair or just not worth it ?