2004 BMW Z4 3.0

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Discussion

TotalControl

8,016 posts

197 months

Monday 25th January 2021
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Love the colour to this. Must be quite rare as I've never seen one in that shade before.

On my bucket list to own at one point. They seem to be looking better with age. Also happy to see that most jobs can, with patience, be tackled yourself.

Jakg

Original Poster:

3,451 posts

167 months

Friday 2nd April 2021
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The wipers never parked properly and always ended up a little way up the screen.

It's a common fault - usually fixed by cleaning the contacts on the wiper motor, but I did this a while ago and it didn't help.

Remembered I still hadn't resolved it so swapped the relay over which seems to have fixed it.

Finding the relays was a little tricky - the fusebox is behind the glovebox, and the relays are on the back, but are only accessible once you remove a couple of screws and the whole thing drops down.



My wifes been driving my E91 a lot more and while it has a spare key, the (rechargeable) battery is dead. I can't solder, so sent it off to someone on eBay to replace. Same situation for the Z4 so did both.

The spare was missing the BMW badge so bought one on eBay.

It made the original key look shabby so I swapped that too. I used some superglue to help hold it, but every time I use superglue I always end up gluing myself to something - and this was no exception!



Despite all the work last time, the coolant light came on again, quick look and I still have a problem...



The coolant was only on the expansion tank - so probably that.

Pulled it out for a proper look but couldn't see anything. I've mentioned before it was swapped in 2015 - seems to be one of those "OE with the logo ground off parts".

Swapped it for a new Meyle one anyway - just a shame that was just £31, but I then spent £25 on coolant again - should've swapped it last time!

Hopefully that cures it.





Also put some fuel in for the first time this year... need to get it out more!

Jakg

Original Poster:

3,451 posts

167 months

Thursday 3rd June 2021
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The interior light was always a bit intermittent, the circuit board inside was a bit distorted. Luckily an E46 part so very cheap.



New spark plugs



Saw a tip online about greasing the shifter pivot bearing.





The leather on the handbrake gaiter wasn't seated correctly and wasn't folded over. I took it to bits and saw a cable tie and thought "oh no, someone's bodged this before", but it turns out that's how it is from the factory - easy to cut it off, reseat and replace though at least.



The door pull trims are a chromed plastic with a matt layer over the top.
Mine have some scratches, but I couldn't seem to find any second hand and are too expensive new to justify.
I saw some recommended from AliExpress and I thought I'd give them a go for £30 - I was nervous the "aluminium" finish might look cheap so went for the carbon option (they are just dipped plastic).



Bit garish up close but blends in well with the rest of the interior.



Edited by Jakg on Wednesday 24th August 10:13

Jakg

Original Poster:

3,451 posts

167 months

Saturday 19th June 2021
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The centre caps were trashed, so I thought I'd try a £5 set off eBay - quite impressed for the price.



I do a lot of driving on country roads and find that fog lights help to illuminate verges at night, so I wired up a previous car so that when the main beam comes on, the front fogs do too - there I used a relay but the wiring wasn't simple.

Spurred on by a post on here, I had a look at a wiring diagram and realised I could do it on the Z4 using a diode between two wires between the light switch module and the fusebox/relays.

Removed the light switch module and got the wiring out so I could test it



All wrapped up



Net result - the fogs work independently as before, but when you put the main beam on they come on too


Jakg

Original Poster:

3,451 posts

167 months

Friday 2nd July 2021
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Moved it.



Edited by Jakg on Friday 2nd July 19:36

The Rotrex Kid

30,191 posts

159 months

Friday 2nd July 2021
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Good update hehe

Love the colour!

Jakg

Original Poster:

3,451 posts

167 months

Thursday 5th August 2021
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Jakg said:
Moved it.



Edited by Jakg on Friday 2nd July 19:36
After years of working on the drive I was super excited to finally get a garage - I had one years ago but never measured it before moving in and realised only the first 15 feet of the car would fit!

Unfortunately, despite being a double, there's not loads of space with tools and a car in there and I've already dropped something on it so I'm trying a car cover - we'll see how annoying it gets for a car I'd like to be using weekly!



I took advantage of an eBay offer and got a new rubber inlet hose - they tear and unmetered air gets in which doesn't help the engine running. I've checked mine before and it looked ok, but this was cheap enough I thought I'd change it.

On the plus side, having access to all of your tools a few steps away is very handy, although the garage needs a lot more lighting.



I removed the airbox/DISA to get it out, although apparently you can do it in situ.





I dropped a bolt, and rather than it disappearing into the gravel, never to be seen again, it was just sitting on the floor. Bliss!

Looking critically, there were some small tears but they didn't look too bad.





Having put it back together though, there's a noticeable difference.

It used to take a few seconds for the idle to level out when it'd been left for a while and that's gone, and I'm sure it sounds better too - but this is probably more noise coming through the sound generator than anything functional.

shalmaneser

5,930 posts

194 months

Thursday 5th August 2021
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Those tears are quite large, IMO. Modern cars rely heavily on their air being accurately metered, under vacuum conditions there would definitely be unmetered (and unfiltered!) air being pulled into the airbox. Might be worth resetting the fuelling adaptions by leaving the battery unconnected for half an hour or so so speed up the relearning process.

Its little improvements like this that really add up to a great feeling car.

C70R

17,596 posts

103 months

Thursday 5th August 2021
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Jakg said:
After years of working on the drive I was super excited to finally get a garage - I had one years ago but never measured it before moving in and realised only the first 15 feet of the car would fit!

Unfortunately, despite being a double, there's not loads of space with tools and a car in there and I've already dropped something on it so I'm trying a car cover - we'll see how annoying it gets for a car I'd like to be using weekly!



I took advantage of an eBay offer and got a new rubber inlet hose - they tear and unmetered air gets in which doesn't help the engine running. I've checked mine before and it looked ok, but this was cheap enough I thought I'd change it.

On the plus side, having access to all of your tools a few steps away is very handy, although the garage needs a lot more lighting.



I removed the airbox/DISA to get it out, although apparently you can do it in situ.





I dropped a bolt, and rather than it disappearing into the gravel, never to be seen again, it was just sitting on the floor. Bliss!

Looking critically, there were some small tears but they didn't look too bad.





Having put it back together though, there's a noticeable difference.

It used to take a few seconds for the idle to level out when it'd been left for a while and that's gone, and I'm sure it sounds better too - but this is probably more noise coming through the sound generator than anything functional.
I had the same issue with tearing on my M54-engined 330ci. It made the car undrivable.

Court_S

12,764 posts

176 months

Sunday 8th August 2021
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It’s seen a fair amount of spannering since I last read the thread. thumbup

I still have a massive soft spot for these.

Jakg

Original Poster:

3,451 posts

167 months

Tuesday 17th August 2021
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When I first got it, it was a right pain to fill with fuel - it'd click off after a couple of litres and would only take fuel at a funny angle.

It seemed to get better over time but it still clicks off every now and again and I'd seen online a faulty fuel vent valve solenoid could cause this, so I swapped it as they are cheap and easy to get to.



The next time I tried to start it, the battery was flat so I put it on charge.

Next time I came to use it, it was a bit rough when starting but figured it was lack of use, but it didn't really clear up and sounded like it was running on 5 cylinders.
Luckily had some tools with me, INPA confirmed a misfire, but when I swapped the coilpacks around the fault codes didn't come back but was still running badly.

Was half hoping it was a battery issue, but thought I'd try cleaning up the idle air control valve first as at idle was where it was worst.
Removed from the car, cleaned with brake cleaner and then left to soak in oil to lubricate it internally.



It was dirty, but not enough to cause a real problem - but as I was working near the intake I was getting a strong smell of fuel...

I'd noticed one of the hoses coming off the fuel vent solenoid seemed to have a lot of slack, a quick tug and it became apparent why



Yep, I'd pulled it off the other end, which was causing the running issues.

Still, how hard can reattaching a hose be, right?



It slides onto a nipple on the back of the inlet manifold - which is inaccessible when installed. When Googling lots of people seem to have this problem when fitting a new solenoid.

I could *just* get my fingers on the nipple with the throttle body removed, but I couldn't see what I was doing, let alone slide the hose on, but it was frustratingly close for an hour.

I refused to remove the inlet manifold fully as it was getting late so I removed some more bits enough to pop it up a bit, and I got the hose on in a couple of seconds (albeit still blind).



3 hours of frustrating garage time later and it's running fine again.

Jakg

Original Poster:

3,451 posts

167 months

Saturday 25th September 2021
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New front discs - they are handed but most dealers only seem to have one side in stock!



£360 (!) later...


Speed1283

1,163 posts

94 months

Sunday 26th September 2021
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Jakg said:
Moved it.



Edited by Jakg on Friday 2nd July 19:36
Lovely car, and a lovely (and rare) colour. You're making me envious, I owned a gun metal grey 3.0 2003 model for 5 years and did a number of road trips in it (gratuitous photo below) I loved that car but eventually moved to the coupe as I just loved the styling that little tiny bit more, although after 7 years and 100k miles I had to change to a 640d due to alot of motorway miles.

Loved both z4 models though, I have a hankering to go back if I ever get a house with a garage.


Jakg

Original Poster:

3,451 posts

167 months

Saturday 19th February 2022
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Cars been getting quite lazy to unlock - I thought it was the lock mechs so I'd put it off because I didn't want to dismantle the doors.

Saw a mention of the GM5 module (body ECU) online - apparently the relays fail, causing the same symptoms.

Out it comes...



Send to a bloke on eBay who replaced the relays and all good now



Winter, lockdowns, WFH, messing around in the garage etc has left me with a flat battery a couple of times. My favourite being getting the car stuck just outside of the garage, unable to close the garage door, in the rain, needing to go out, and trying desperately to push it back inside uphill before digging out the jump leads...

I've got a trickle charger, but connecting it was a pain so I never used it.
It's an old Banner that uses the TM71 connector - while I couldn't use the Ctek quick comfort connectors everyone raves about, I could use the Optimate equivalent. Mounted in the boot direct the battery, with the boot closed on the cable it seals nicely.



I've previously extended the 12v lead so for now it runs into the roof and then drops down for the car.
I can guarantee I'll drive off with it connected so I've wrapped it in foil / blue tape to make it more visible.



Now officially a garage queen...



Long term my garage needs sorting out, more sockets etc - but it'll do for now.

Jakg

Original Poster:

3,451 posts

167 months

Saturday 19th February 2022
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I've fitted hidden USB chargers for phones in various cars, I usually use these as they can be hidden and charge at a decent speed. Plus they are like £3.



The car came with one already fitted for a centre console USB port, I added another wired off this.

But they don't support fast charge (i.e. my iPhone will take a max of 10w).

I was looking for a USB C equivalent that'd support fast charge - I looked everywhere for a module I could hide, but I just couldn't find one.
I found some panel mount ones but after buying one found out it needs to be turned on first... every time. So that was out.

Eventually I gave up and went for the simple option - a panel mount 12v socket and a cigarette lighter USB C adaptor.

I fitted it in the glovebox. Panel mount was a bit tricky as there's not much space in the Z4 behind the glovebox



Careful positioning later and when closed it fits around the fusebox and dash supports



And fitted



Now I can charge my phone at 15w



And as a bonus, I can charge my USB-C MacBook as well (albeit at 18w)



(this is actually taken in my 335d, but I've done the same job on both cars...)

Jakg

Original Poster:

3,451 posts

167 months

Saturday 23rd April 2022
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The brake fluid reservoir has an integrated level sensor, the sensor is glued to the reservoir itself. Only mine wasn't glued anymore...



The reservoirs are available separately but I couldn't find one at a reasonable price, but loads of servos+reservoirs were available.

They are common to early E46's as well, but the design was slightly different - the extra blanked off bit on the bottom of mine wasn't present. I didn't want to risk it so ended up finding a Z4 one.

I left the servo in place and just swapped over the reservoirs which was quite simple once I'd sucked all the brake fluid out.





Edited by Jakg on Wednesday 22 March 11:44

Jakg

Original Poster:

3,451 posts

167 months

Saturday 23rd April 2022
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MOT was due so booked it in, but thought I'd take it for a quick spin first to check everything was ok... it wasn't.

No power steering, power steering light on the dash and the sport button didn't do anything.

A Google later suggested that the electric power steering motor was the culprit - it fails and causes an issue with communication that stops the sport button working as well.
INPA wouldn't connect to it either, so it was looking likely.

The motor is on the side of the steering column, and in the factory goes in before the dashboard...

I did check the supply voltages hoping it would be a simple fix, but unfortunately not.



I found this video which covered the removal process, which looked involved but not too difficult - https://www.youtube.com/watch?v=K00JRcr7Ivk

I removed the drivers seat for more space, and had the roof down so I could lie in the footwell upside down.

Being able to leave it parked without a roof or seats or central locking (battery disconnected) in the garage was very handy. I don't know what I would've done without a garage...

Wheel, clock spring and switches out:



The video talked about removing the whole steering column, but I'd seen online that you only had to loosen it to get the motor out.
But there's not much room in the dash, and you basically need to do all the work to remove it anyway, so I thought I'd do that to make life easier - this was a mistake!

The column is attached with a UJ to the intermediate shaft.



In the video this just pulls off, but mine was totally seized.

After lots of penetrant, hitting with hammers, screw drivers etc I finally found something to get it moving - a small crowbar at just the right angle



Unfortunately from here things got worse.

Although I'd started it moving, I couldn't get it properly free.
And I couldn't get the column out anyway, because the motor was fouling on the metal dash supports



You can see the motor to the right of the column.

So I ended up removing the motor with the column loose like I was trying to avoid in the first place.



With the motor removed, a tug on the column and it was free.





I sent the motor off to ECUTesting and £300 later it was quickly back with me.

I put the column in first and then put the motor on in the dash - the ring on the column is adjustable (changes how the motor assists), so added some paint marks to ensure it went together as it was removed



Put it together and the power steering light has gone.
I did have an airbag fault light from having the seat out which I've since cleared.

Unfortunately, it didn't feel very good...



Massive play at the wheel that made it undrivable. I took it for a quick spin and it was wandering all over the road without any steering adjustment, scary.

After some poking around, spotted this



The two ends of the intermediate steering shaft appear to be turning at different speeds.

Removal should've been simple but I just couldn't it to compress enough to get it out, which is the same problem I had when I was taking the column out.
There was absolutely no way I was taking the column out again, so I dismounted the rack instead.

The problem was now much clearer



I got a second hand one and that was totally solid, and adjusted properly in as well.



In hindsight I think my shaft was already seized up which is why I struggled getting it disconnected at the column end - it just wouldn't compress as far as it should do. And then getting aggressive with it probably finished it off.

The good news is that the wheel, column, shaft and rack are all keyed so you can only put them in the right orientation.

The bad news is that with the shaft disconnected and then with the rack disconnected from the chassis, the wheels will very easily move side to side.



This meant the first time I assembled it, I was 360° out so had like half a turn of lock one way.
Luckily I expected this might happen and I could easily get it aligned properly.

All back together, drives fine, no fault codes.
Took it for a spin, all good.
Took it for the MOT this morning, passed with no advisories!

Unfortunately when I picked it up, it's got a bunch of dash lights on, and they had it plugged in to a Snap-On Solus tool when I got back and told me there were like 10 error codes.
I'm not really sure why they were diagnosing it after an MOT anyway, but hey-ho, something else for me to have a look at...

Edited by Jakg on Saturday 4th June 20:20


Edited by Jakg on Wednesday 24th August 10:18


Edited by Jakg on Saturday 10th June 23:27

Jakg

Original Poster:

3,451 posts

167 months

Thursday 8th September 2022
quotequote all
The inlet manifold has some rubber bungs on the back



They are cheap from BMW (like £1) so replaced a couple - I didn't have any problems before, but if you compare old and new you can see they were past it



Put some standard brakes on



And some shiny new nipples - and at the same time the hoses as the standard ones had cuts in them



Put some standard seats back in



Cleaned it up (even polished) and took some nice pictures





Sold it

:'(

Consumables, Servicing, Repairs & Appreciation (thanks used car price bubble) came to £0.22 per mile - this would've been a lot lower, if I'd done more than 10k miles in 4 years!
Fuel at 28.8 MPG - £0.27 per mile at today's prices
Plus tax / insurance.

Edited by Jakg on Thursday 8th September 22:53

C70R

17,596 posts

103 months

Friday 9th September 2022
quotequote all
I've been keeping an eye on Z4 values, with a view to getting back into a manual later this year. It looks like £5-5.5k is the starting point for anything worth keeping. Do you mind letting on what price you got, and how many miles?

Jakg

Original Poster:

3,451 posts

167 months

Friday 9th September 2022
quotequote all
C70R said:
I've been keeping an eye on Z4 values, with a view to getting back into a manual later this year. It looks like £5-5.5k is the starting point for anything worth keeping. Do you mind letting on what price you got, and how many miles?
£3,900, 120k.

I found it tricky to price - asking prices are really high, but those cars aren't selling.