2004 BMW Z4 3.0

2004 BMW Z4 3.0

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Discussion

Jakg

Original Poster:

2,402 posts

123 months

Tuesday 21st August 2018
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parabolica said:
How long start to finish did the VANOS job take OP? I've been thinking about doing mine at some point but wasn't sure how much time to budget for.
Took me probably about 8 hours over 2 days but I'm very slow and access is very poor on Z4.

Jakg

Original Poster:

2,402 posts

123 months

Sunday 2nd September 2018
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Headlights have been letting the front down, gone all cloudy.



Used one of the 3M kits to bring it back. The first step involves some quite abrasive material which always makes me think "What have I done!" as it takes your slightly-crazed headlights and makes them look like they've been sandblasted.



Through the rest of the steps and I ended up with this





Much better. Won't last forever, but not bad for an hours work and £20.

parabolica

5,295 posts

139 months

Sunday 2nd September 2018
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Make sure you seal them with something like a ceramic glaze; I did mine a few months ago just before the really hot weather and they've already started to yellow again, although you're might last longer as we probably won't have as much sun for the rest of the year.

Braintax

311 posts

142 months

Sunday 2nd September 2018
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Enjoyed reading about your efforts with this car. I also had a 2004 3.0 roadster about 8 years ago now and thoroughly enjoyed the car. Like yours my amp was temperamental. My roof motor packed in (it's a case of when not if with these, unless you relocate or are lucky enough to have a garage) and it tramlined like, well, a tram...

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.

I found the M54 was really good on fuel, often averaging 34mpg over a tank. If you can find yourself a hardtop for a decent price then be sure to snap it up, it's a great looking piece that makes them a much nicer place to be in the winter.




Mr Tidy

11,344 posts

82 months

Monday 3rd September 2018
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If you are ever looking for a hardtop, or any other bits for that matter, z4forum is worth a visit. thumbup

Jakg

Original Poster:

2,402 posts

123 months

Sunday 9th December 2018
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My car has the standard seats, and they are useless. Leather, and quite comfy, but with absolutely no lateral support. Going round corners you had to try to hold yourself upright in the seats.

An easy upgrade is the sports seats from a Z4, but these are very expensive second hand (£1k!). Alternatively, E46 seats are supposed to be a drop in replacement, but I wasn't keen on the look of M3 ones.



I found someone had made up S2000 seats by making adaptor plates up and thought I'd give it a go - but with a twist.

I've always like the Corsa VXR Recaro seats and supposedly (incorrectly, it turns out) they should fit in my Megane if I couldn't fit them here, so I picked up a set. Because they are common they are quite a bit cheaper than you'd expect - I paid £350.

I then picked up another set, because why not. Good job I just finished extending my spare bedroom...



Made adaptor plates up out of 6mm steel. The S2000 seats I'd seen fitted used box section, but I knew that the height of the seat would be an issue so I had to do everything possible to keep them low.



Many grinder discs and drill bits were sacrificed.

I couldn't work out how to use the electric seat runners from the Z4 seats, so decided to use the Corsa runners instead, but they needed quite a bit of modification.

Using the Corsa runners means everything still works, inc the button to fold and slide the seats forward.





I'm aware I'm no pro fabricator...



The channel in the runners was so narrow I even had to grind the nuts down a tad to clear it



Out with the old



In with the new







The good:
The seats are ace.
No less comfy than the standard seats, but so much more supportive.
The car actually feels like it handles better too, probably because you are much more comfortable driving the car without having to hold yourself up!

The bad:
The seats are much bigger than the Z4 ones, which are actually tiny. The Z4 doesn't even have seat airbags - they are in the doors instead.
Because they are bigger, they don't go back as far - but luckily they go just as far back as I need them.
They sit a little higher than the Z4 seats.

However, I think I would've had these problems with any other non-Z4 seats.

Jakg

Original Poster:

2,402 posts

123 months

Sunday 17th March 2019
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First MOT in my ownership - failed on corroded brake pipes, which was an advisory before so not too bad.

Garage replaced them and at the same time got them to replace all the fluid with ATE Type 200, and all the bleed nipples with some new stainless HEL ones as the existing ones were starting to round.



An advisory on worn ball joints so did those, too.

Annoyingly on my Megane a front balljoint is £15 and can be pressed in and out of the arm in situ. On the Z4 you need a whole new arm (£64) - although I went for Meyle HD arms where the balljoints are replaceable in the future (but they are still £30).



Access to the middle bolts on the arm was quite tricky, from the bottom you've got 1/8th a turn max using a spanner, and from above you need to use a bunch of extensions & UJs





The other side access was even worse, which was annoying as rust had made the bolt mega-tight - you can just about make out the nut next to the engine mount.

Even went to Halfords to get some wobble extensions, but just couldn't line it up, so spanner it was - the force of undoing it has literally made my hand swell!



Got them out in the end though



When I changed the wishbone bushes, I was a bit lazy and didn't bother lining the carrier up over the collets on the chassis properly, just started doing the bolts up and thought it'd bring the carrier home on it's own. Nope, it just damaged the threads as it wasn't lined up right...

The top bolt did start to tighten but it then it started to get looser again and that's when I knew I'd done it. Left it at the time but I knew I had to fix it.

Borrowed a Helicoil kit and although I was a bit terrified it turned out ok in the end.

My suggestion is to loosely insert the ball joints first, put the nut on but don't tighten at all. Then get the bush lined up properly over the collets, and put the bolts in tight enough to keep it on them, but loose enough it can move. All the guides say to do the bushes last - but then you end up with very little play so it's a real pain to line up (which was why I rushed it last time).



Note I said the *top* one was worn out. I forgot that and drilled out the perfectly good bottom one first, oops.

Torqued up fine though the second time round so alls well.

My assistant wasn't much help either.



Some of the "vagueness" in the steering has gone and the tramlining has reduced a little too which is good. Now need to work out if I want to get it aligned again (would be the third time in less than a year...)

dave_s13

12,434 posts

224 months

Sunday 17th March 2019
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Good work mate, enjoyed reading this stuff. Im the dubiously proud owner of an e93 with the N53 3.0 engine, so it's kinda related to yours in that it's a convertible, a BMW and can break in very expensive ways at any time for no reason

It looks lovely though and is great to drive, same as yours. The e93 doesn't tramline at all though, doesn't that do your nut in?

Jakg

Original Poster:

2,402 posts

123 months

Sunday 17th March 2019
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dave_s13 said:
The e93 doesn't tramline at all though, doesn't that do your nut in?
Yes! Not my daily driver, and not something I'd choose for a long motorway journey so I'll tolerate it.

I've got a new pair of (non-runflat) tyres in the shed but I feel silly putting them on as the runflats on the front still have >4mm.

Hopefully that should cure it.

Mr Tidy

11,344 posts

82 months

Sunday 17th March 2019
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On the topic of tram-lining I've had 4 BMWs with run-flats, and 2 that had non run-flats.

Neither of the E46s without run-flats ever did it.

Both Z4s on Bridgestone RFTs did it a lot!

My E87 and E91 on Pirelli RFTs did it a bit, but nothing like as bad as the Z4s.

When my current Z4 needs tyres I'll have to decide whether I want to stay on RFTs - but even if I do they won't be Bridgestone! laugh

illmonkey

12,851 posts

153 months

Monday 18th March 2019
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Good to see you've poly'd the wishbone to chassis too.

My old Z4 tramlined like crazy, new tyres sorted it, but I understand not wanted to waste your current tyres!

These cars are great bang for your buck. Bit of DIY is helpful too. Roll on spring eh!

shalmaneser

4,068 posts

150 months

Monday 18th March 2019
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Interesting about the vxr seats. I really don't rate the leather seats in my M3 and would be interested in trying to get the vxr seats instead. They look an awful lot more supportive!

SamJB

62 posts

86 months

Tuesday 19th March 2019
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Had some of the same tramlining issues on my old E85 and funnily enough, similar issues with a garage's alignment settings for sport and normal suspension.

Fitting the larger front anti roll bar off of an E46 M3 made a huge difference for me, you can pick them up for peanuts from ebay and they'll bolt right up.

I also had the alignment done properly by a local Lotus specialist after the Hunter machines had messed the rear alignment up to the point that going over a wet man hole cover would cause the rear to drastically throw out sideways. I'd recommend finding someone that will road test what they've done and apply some experience to it rather than just making the lights go green then hoping for the best.

Mr Tidy

11,344 posts

82 months

Tuesday 19th March 2019
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Back on the seat topic, I believe Mazda RX-8 seats are another popular option to put in Z4s.

Jakg

Original Poster:

2,402 posts

123 months

Tuesday 19th March 2019
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SamJB said:
Fitting the larger front anti roll bar off of an E46 M3 made a huge difference for me, you can pick them up for peanuts from ebay and they'll bolt right up.
It looks like only the front fits, not the rear - I'm way of stiffening up the front at the expense of increasing understeer. Not that I have a problem with that at the moment.

SamJB

62 posts

86 months

Friday 22nd March 2019
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Jakg said:
SamJB said:
Fitting the larger front anti roll bar off of an E46 M3 made a huge difference for me, you can pick them up for peanuts from ebay and they'll bolt right up.
It looks like only the front fits, not the rear - I'm way of stiffening up the front at the expense of increasing understeer. Not that I have a problem with that at the moment.
You can fit any aftermarket rear anti roll bar from and E46 3 series but I'd try out just the front one first.
I feel you'd need far more than an anti roll bar on the front of these to stiffen it enough to promote understeer.

helix402

5,528 posts

137 months

Friday 22nd March 2019
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In theory a thicker front arb without a thicker rear bar to match will increase understeer.

In reality on an E46 chassis based vehicle an M3 front bar will not increase understeer but will reduce roll.

I have one on my 330d Touring along with a 328Ci rear bar.

CousinDupree

608 posts

22 months

Saturday 23rd March 2019
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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!

Jakg

Original Poster:

2,402 posts

123 months

Saturday 6th July 2019
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Catching up on the servicing meant a day of fluids.

Jacked it up level.





Coolant replaced.

Gearbox & diff oil replaced with a magnetic sump plug on each.
Diff oil was fine but gearbox oil was almost black.

Gearbox is an awkward fill so one of these pumps was super handy.



Then some driving!


Jakg

Original Poster:

2,402 posts

123 months

Saturday 6th July 2019
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Jakg said:
I've just got to remember that this is supposed to be a cheap entry into the world of convertibles and resist the urge to start modifying it...
I’ve always been contemplating a brake upgrade.

As standard it has 300mm discs and single-piston calipers at the front



Bit weak for a 155MPH car. My diesel Megane has Brembo 4-piston calipers from the factory!

I did an autosolo and not only did I start to feel the pedal getting longer, but at the end of the day the brake warning light came on and somehow the brake master cylinder was overflowing.



I have no idea how this happens - the brake fluid was changed and flushed when the brake pipes went on a couple of months ago, and brake fluid doesn’t expand to my knowledge, so…

There were a couple of routes available:

1 - E46 330i / Z4 3.0si 325mm
Straight fit, easily available, but because of their popularity the carriers + calipers sell for about £100
I’ve done this upgrade on my old MG ZT (it uses E46 brakes) in the past as was impressed.

But they are still single-piston and I thought maybe I could try something different.

2 - E82 135i 6-pot

I liked this idea, but simply couldn’t find any. They were only ever fitted to the E82 135i, which isn’t that commonly broken.

3 - Porsche Brembo Calipers + Brackets

Much more like it, but the brackets aren’t cheap and the popularity means the calipers aren’t either.

4 - F30 M-performance Brembo Calipers
Came across someone fitting them to an E46 - https://forum.e46fanatics.com/showthread.php?t=107... and piqued my interest - bolt on and eaily available.

Picked these up for a little over £200 because they’d been painted red absolutely terribly.



After some wire wheel action it turns out they are supposed to be silver.



Because they are only a few years old they were in very good condition.

I also got a spare set of rear calipers to refurb.
This was harder than it sounds, because there are a handful of calipers or carriers used on E46/Z4s, but in various configurations. I think it ended up being something daft like an 02-04 325i/328i but nothing else fitted!
Being about 15 years old they were in way worse condition, rust etc. I tried a wire wheel and my ultrasonic cleaner but it wasn’t making much difference.

Ended up trying electrolysis - https://www.the75andztclub.co.uk/forum/showthread....





The layer of scum and slime that formed on top was absolutely disgusting.



They didn’t come out perfect, but most of the rust was easily removed after.

The car had red calipers fitted which I’ve never thought was a great look on a dark-red car.
I’ve spray painted calipers in the past but never really been happy with the finish, so I tried a different kind of kit this time, from BCS Autotmotive - https://www.bcs-automotive.co.uk/shop/brake-calipe...
Went for gunmetal, this is the ad picture…



Primed



First coat



Second coat



Thought they looked a bit weird plain so went for some stickers. I know this will be divisive!
From the factory they can come as part of the “M Performance Brakes” pack with the //M sticker so I don’t feel *too* bad about it.
They are supposed to be upside down (or at least, thats how BMW do it) on one of the calipers.



Lacquer over the top and then baked



Unfortunately - disaster



I think some brake fluid leaked out while in the oven and ate off the paint. Luckily as it’s brush-on, localised repairs were very easy.

I overhauled the rear calipers (seals, dust boots, sliders, slide bushes), but left the fronts as they were so new.

Overall the kit wasn’t cheap, especially not when I had to buy primer and lacquer on top. And being a brush-on kit, you get brush marks. That works ok for a metallic gunmetal finish, but for a flatter colour I doubt it would. Not sure what I’d do next time!


Then it was fitting time.

Straight off the bat I had problems, the disc retaining screws both rounded off despite doing everything properly.
Ended up using a chisel to tap them out.



I’m using 345mm Z4M / E46 M3 CSL front discs. I got a second hand set in case they didn’t fit as they are quite pricey. I’ll try to get a new set later on.



The pad retaining pins I’d bought didn’t fit so I had to use the original ones - note how the (new) top pin hasn’t gone across anywhere near as far as the (old) bottom one



It didn’t have a chamfer on the end so it didn’t lock in place, either.






I initially used F30 brake hoses as per the guide but the length was too long and the grommets weren’t right so I get a set made up by HEL.

I couldn’t get the rear hoses fitted properly as the unions on both sides were totally seized and just rounded off.



Ended up replacing the whole lot with braided hoses at the back, too.

When reassembling I accidentally torqued the rear carriers up to 110nm (as per the fronts), not 65nm, so needed new bolts, too. Luckily they came out without too much hassle.



When trying to bleed the brakes my Eezibleed started leaking again (this is my second, and has already had new o-rings to combat the last leak!).

I splashed out on a a Sealey bleeder - half the reviews said it was fantastic, half said it leaked. Mine turned up and leaked - until I found a tip online to put silicone grease around the cap and it was fine. Way easier than trying to deflate a spare tyre to the right pressure.

Flushed another litre of ATE Type 200 brake fluid through and bleed the clutch as well in case I had any contaminated fluid.

I had to fit larger spacers than I’d like to clear the calipers



I had a horrible moment when I put the wheels back on as they stuck out miles!



Luckily when back on the wheels it turned out ok, but I will look into ways to bring them in a bit







Only fitted them the other day so rubbish pictures. A little too early to give lots of feedback - but they do at least work!