2004 BMW Z4 3.0

[Jakg]

NorthernSky said:

Oh and as others have said, treat the car to new tyres all round and get them aligned, ditch the runflats. Hopeless on UK potholed roads!

Sticks. said:

I kept my rfts for quite a while. Although getting rid is an improvement, it's nothing like an E46 on mismatched tyres.

Not just tramlining though, the car felt less unsettled my small bumps, more planted, almost lower. In short, like you'd have expected it to.

Braintax said:

Like the earlier poster in this thread, my car's steering would tighten up in the summer and it really, really wasn't pleasant. As others have mentioned, the best thing I ever did was to switch to non-runflat tyres, I went through Falken FK452s and Uniroyal Rain Sport 3s, both of which were pretty excellent and really transformed the car.

CousinDupree said:

Great progress. Can't help but think you are still missing a trick though.

Fitting a new set of good tyres is the most cost effective improvement you can make, especially if you are junking runflats.

It's all a bit of a crapshoot until you do that. A new set of F1 Assym 3s transformed my Z4 3.2. Steering, ride, traction, tramlining....

Not expensive either!

rooflesstyrant said:

Are you still on runflats even after the suspension upgrade and the trackday? Probably need a dry track day or two to wear out those tyres.

Can you sense a consensus?

Runflats have gone, now on a set of Vredestein Ultrac Vorti's. Used Vredesteins for years and really rate them.

Tramlining disappeared, and ride is better.

Getting the tyres fitted was a bit of a disaster, though. I've used the same tyre fitters for years - they used to do decent prices on tyres, but they started quoting silly prices (i.e. £50 a corner more than I could buy online) but were happy to fit ones I supplied. A while ago I went in and the boss served me, who moaned the entire time about how I was supplying tyres and it left a really sour taste. But later they were fine.

Four tyres won't fit in a Z4 (I could get one in the boot, one in the front) so a friend dropped the other two off and I got served by the boss again - as soon as I mentioned I had tyres, he signed and demanded to see the car, see the wheels, see the tyres, moaned about me supplying tyres and was just generally difficult. And then said it'd be £20+VAT a corner - normally it's £10!

If I could've put the tyres back in the car I'd of left then and there but I was stuck so had to put up with it.

2 and a half hours later the cars done, and I immediately notice some damage on the wheel. The boss is a bit evasive about letting me look at the car before paying and when I mention what I've seen, out comes the sighs again

By fluke I had a picture of the wheel from the other day



And now



At the top there's clearly a fresh bit of impact damage that's gone through the lacquer, and then the rest of the lacquer has started to peel.

They couldn't claim they hadn't done it, so then the paint finish on the wheels was blamed. Couldn't really argue the point so now I'm stuck.

Overall, left a sour taste and definitely won't be going back.

Moving on...

MOT failed on a drop link split boot so that got changed

Old one



Probably could just've reseated the boot but I've got this far



Always annoying that aftermarket parts use different sized bolts to standard ones - half way through an 18mm spanner had to be slimmed down to counter hold.



Shiny new one fitted



Got a chip in the windscreen and it turns out I don't have windscreen cover - ooops.

AutoGlass wanted £70 to fix a chip (?!?!) so I'd planned on leaving it but I saw someone mention the cheap repair kits and thought I'd try it.



Difficult to photo the before / after but it's done a fantastic job - the piston pushes the resin into the spider cracks so they disappear and there's only a faint mark visible of the centre of the chip. Not bad for a fiver and 20 minutes.

Scanning with INPA showed a fault code for one of the cylinder so after swapping coilpacks around to diagnose, two new ones were fitted.

Finally, it's got another driveway friend



I now have two very different 6 cylinder BMWs - https://www.pistonheads.com/gassing/topic.asp?h=0&...

Also, you can tell I really need to wash cars more often.

Edited by Jakg on Wednesday 24th August 10:10

[Mr Tidy]

That's some impressive spannering OP!

And welcome to the two world of owning two 6 cylinder BMWs. I've been doing that for just over 5 years now and there isn't anything I would rather have.

[C70R]

Big fan of the car, and your willingness to get grubby. I've come close to picking one of these up a few times, but ended up plumping for a Mini instead.

Can you share a link for the windscreen chip kit you used? I have a very annoying one that isn't quite an MOT failure, and I quite like the idea of spending a couple of quid on an 'ok' fix.

[Jakg]

C70R said:

Can you share a link for the windscreen chip kit you used? I have a very annoying one that isn't quite an MOT failure, and I quite like the idea of spending a couple of quid on an 'ok' fix.

https://www.ebay.co.uk/itm/DIY-Premium-Car-Windscreen-Repair-Kit-Crack-Chip-Windshield-Glass-Window-Screen/153688776924

The recommendation I saw on Facebook was from someone who bought the same kit in Asda for about a fiver if you prefer to shop local.

[Sycamore]

Could you shine some light on the cable you use to connect the car to INPA?

I have the full set of software and the DCables cable I have connects and I can read live data from the car, however as soon as I try dig any deeper, read fault codes etc it says it can't connect to the car. Assuming it's a fault with the cable itself.

I have the same car, same colour, same engine, so I'm hoping that's the case. Or I am thick, which is a real possibility.

[C70R]

Thank you.

[Jakg]

Sycamore said:

Could you shine some light on the cable you use to connect the car to INPA?

I have the full set of software and the DCables cable I have connects and I can read live data from the car, however as soon as I try dig any deeper, read fault codes etc it says it can't connect to the car. Assuming it's a fault with the cable itself.

I have the same car, same colour, same engine, so I'm hoping that's the case. Or I am thick, which is a real possibility.

https://www.ebay.co.uk/itm/312801859524

The switch swaps two pins and that is the key I think - I had a similar unit before where I added the switch myself and after that it worked on my MG ZT & the Z4. This is probably why yours isn't working?

Plus you need the right version of the software (I think the version included is ok), and to ensure that the COM ports are configured correctly (i.e. that the interface software is pointing at the COM port associated with the cable).

[Jakg]

The boot continues to be bigger than expected.

Work bag, swimming bag and an entire office chair - albeit completely dismantled.



And an arty profile shot

[Jakg]

Was driving along a while ago and the battery light came on and lost power steering.

Thought it was just lack of use, so took it out later and it was fine.
Stopped on the way back to make a phone call and noticed the roof wouldn't go up. And then the power steering stopped working again.
Very luckily I wasn't far from home, started to run poorly before eventually conking out on the drive.
Although it was on the drive, unfortunately it was blocking my other car - and had the roof down - so I tried jumping it and it started fine.



With the engine running, the problem is obvious



Airbox out



Alternator off





I thought it'd be a straight replacement, but it was a bit more expensive than I was expecting - the fitment is unique to the Z4, but I suspect any M54 one would fit - even then it was £130 for the cheapest recon unit.
I took a chance and replaced just the voltage regulator for £30.



And sucess



Unfortunately, while poking around I found a suspicious coolant puddle on the undertray



First thought was the expansion tank, so I pulled that out to find out it'd already been replaced in 2015 (that was in the service history, ooops).

I noticed the seals on the expansion tank cap were looking a bit worn out, but that wouldn't explain that much coolant.



Some more poking around and I spotted a little bit of coolant around the temperature sensor



Pulled it out and it looks fine



Having looked online they never leak... unless they've been in there a while, then if they are ever removed they never seal again.
I removed it when doing the VANOS seals so fair enough.

The O-Ring isn't a separate part, and all the measurements I could fine online were imperial, so I got a new one for £15.

I originally thought the leak was from the thermostat above, but although I'd realised it wasn't, I got a brand new Wahler one on eBay for £15 so I thought I'd change it anyway.
The bolts were really rusty, and there was coolant stains around the outside of the gasket so I think it has been leaking for a while, although probably not badly. And obviously new bolts too.



Baby monitor makes nap time, car time



Put it all back together, trying to bleed the system and the stupid plastic bleed screw rounded



I get why it's plastic, and i'm probably guilty of overtightening it slightly, but I think the real problem is that I don't know what tool is best to use on it.
It's a cross head, but no depth so you can't use a crosshead screwdriver.
And if you use a flat head it needs to be really wide but also thin to fit in the grooves without putting the torque in the weak centre.

I borrowed the one off my 335d to bleed it and then replaced both cars with brass ones



I've bled the system before but this time I wasn't happy with the heat coming out of the vents, it was probably the scare stories of the M54 being difficult to bleed.
One suggestion was to raise the front - I couldn't be bothered to jack it up so found a nearby incline instead.



I think the drive probably did the job though as it was fine when I got there!

I worked out how many miles it's done this year and i'm genuinely embarrassed… need to drive it more, pandemic dependant.

Edited by Jakg on Saturday 27th January 20:19

[helix402]

Best tool for undoing the bleed screw is a 2p. The radiator outlet temp sensor o ring is a common leak point on all M54s and is available from a few suppliers as an uprated version.

Edited by helix402 on Friday 22 January 23:55

Edited by helix402 on Saturday 23 January 14:31

[Sticks.]

Good write up thanks.

I had the sensor replaced last year as it was leaking. The hose connection has leaked previously.

[greggy50]

Good thread, I was the owner of the Z4 linked in the OP and regret selling it when I did as prices appear to have risen a fair bit recently looking at ones for sale currently...

I may look at getting a Z4 3.0 SI later in the year if I can find one decent for under £7k

[LosingGrip]

I’m half tempted by one, although the one I’ve looked at is auto.

What are they like for tall people? I’m 6ft 4 and not sure if I’ll be able to drive it comfortably.

[helix402]

LosingGrip said:

I’m half tempted by one, although the one I’ve looked at is auto.

What are they like for tall people? I’m 6ft 4 and not sure if I’ll be able to drive it comfortably.

You’ll fit.

[d_a_n1979]

helix402 said:

LosingGrip said:

I’m half tempted by one, although the one I’ve looked at is auto.

What are they like for tall people? I’m 6ft 4 and not sure if I’ll be able to drive it comfortably.

You’ll fit.

Depends on your build.

I can't fit in one at all, but I'm 6ft 4 and 22 stone.

Even a lot lighter at 18stone I couldn't fit in one comfortable enough to drive more than a spirited drive...

[LosingGrip]

d_a_n1979 said:

Depends on your build.

I can't fit in one at all, but I'm 6ft 4 and 22 stone.

Even a lot lighter at 18stone I couldn't fit in one comfortable enough to drive more than a spirited drive...

Ah I’m the same weight give or take. Will see if I’m allowed to test drive one with COVID etc.

[d_a_n1979]

LosingGrip said:

d_a_n1979 said:

Depends on your build.

I can't fit in one at all, but I'm 6ft 4 and 22 stone.

Even a lot lighter at 18stone I couldn't fit in one comfortable enough to drive more than a spirited drive...

Ah I’m the same weight give or take. Will see if I’m allowed to test drive one with COVID etc.

The issue for me is my width of my back, shoulders, arse and legs

I'm a competitive powerlifter and stone lifter, so it's my build that makes it awkward for me unfortunately...

[LosingGrip]

d_a_n1979 said:

The issue for me is my width of my back, shoulders, arse and legs

I'm a competitive powerlifter and stone lifter, so it's my build that makes it awkward for me unfortunately...

I wish I had that excuse...I’m just fat.

[Sticks.]

i remember reading on the Z4 Forum many years ago that some people found the sports seats too narrow. SE seats might be better, absolutely no support at all.

[beambeam1]

Sports seats were hellish but I managed Edinburgh to the Nurburgring for 8 laps and back 10 years ago and I was 6ft 2" and 22 stone then. I'm broad as well as a bit husky but it was the legs that killed me, had to replace the door handle trims as my knees rubbed off them the whole trip.