Interlagos Z4M Roadster - The Spicy Meatball

[GazHyde]

Front end refresh!

As posted above I ordered the following parts and we had a spare lift available today, so...

• Front discs.
• EBC Yellowstuff pads
• Meyle HD control arms
• Powerflex front wishbone rear bush (offers additional +0.5° of caster aimed at offering greater precision with improved geometry)
• Inner / outer tie rods - after a bit of research I've managed to figure out Meyle HD parts for a third of the price of OEM.
• Meyle drop links

As with the back everything a bit tired up front and I have a brake vibration so makes sense to drop another small fortune and tank the lot in one go. I'm getting more impressed with the Meyle HD quality each time I order them considering the vast difference in price over BMW.

Also particularly helped with the fact that most of the Z4M front end is standard E46 parts bin making it really easy to find parts. This isn't a "how to" thread, just some random pics I took as we worked.

Before pics:

Wishbones look original, but then I'm sure everything we changed probably was as well.

New Meyle HD outer tie rods, ignore the drop links (I'll explain why they are wrong later)

The finish on Meyle HD parts like to coating on these inner tie rods is excellent.

Meyle HD wishbones

Removing the old rear wishbone bushes, simple case of hack saw through the rubber and out cut through the outer bush then punch out. Z4M bushes are unique due to the design of the solid rubber bush, non M are fluid filled.

The Powerflex bushes are a solid aluminium with a push in poly bush insert, also designed to give an extra .5degree +ve castor angle. Fitting these are not for the feint of heart and took way too much time a fettling. They are an interference fit and there is no tolerance, if anything possible fractionally oversize. We ended up reaming out the inner part of the holder with a flappy disc on a drill - taking care not to take too much material of. Even after this work it took a lot of patience and grease on the 12t press to align them. Utterly ridiculous but we got there eventually.

We got distracted at this point by the adults ice cream van turning up outside...

I only use Yellow Stuff pads, not used anything else for the last 5 years or so. Why fix what isn't broken!

These discs were more expensive than replacing front and rears on my old 3.0si including pads. But they look epic! Same discs as used on the M3 CSL.

Quick look underneath just before final tightening and checking over.

Then off to our local tame wheel alignment centre for a full 4 wheel alignment. Lee knows these guys and they are happy for him to discuss and direct the technician as he works (costs us extra in donuts!). Test drive home and she's mint!

A note about drop links. I ordered standard E46 drop links which should work fine on a standard Z4M from what I found out. However I didn't realised I'd need shorter ones as I have BC BR coilovers fitted. Luckily we had a shorter set of Meyle HD in stock from an old set of KW Coilovers fitted to another Z4. They seem to be about the correct size so will run them for a while and worst case we can swap them for different ones. However no knocks, bangs or odd handling so we should be good for now.

 

[GazHyde]

A little bit about part ordering being the same philosophy as the rear end rebuild - either OEM BMW parts or better than BMW parts (subjective of course) where available.

Tie rods, this is a bit of a doozy! Item 4 & 5 are complete tie rod kits. You can see that parts 4 & 5 as shown are a kit comprising inner and outer tie rods. However when you look at the diagram the inner tie rod doesn't have a part number. It's also not listed separately in the part table.

The only other section I could think of would be under power steering and it looks like the inner tie rods are part of the rack assembly. Again no separate part number.

After much investigation I found a post somewhere else which mentioned an alternate part someone had identified, but they never came back to update the thread to say it was correct or not. So armed with this information I figured that a standard E46 inner tie rod should work, which also fits in with generally with various standard E46 parts being compatible.

A pair of Meyle P/N 3160304600 were ordered and fit perfectly!

So why didn't I just buy the full tie rod kit from BMW then? lllparts quoting around £150 a side. The Meyle HD versions were £40 a pair for the inners and £38.50 a pair for the outers - so just about half the price.

Wishbones:

Similar picture here with Meyle HD at £161.88 a pair, and lllparts at about the same per side. Standard Z4 / E46 part.

 

[Althulas]

Quite a good saving Gaz, impressed with the finish on those inner arms.

 

[Sajk]

Have you done the valve shims? If so what shim kit did you order. They seem to vary a great deal in price

 

[GazHyde]

Have you done the valve shims? If so what shim kit did you order. They seem to vary a great deal in price

Mines due a Inspection 2 service in September and that's included as part of it. Will be going to my trusted local independent so will be whatever he uses I guess.

 

[GazHyde]

Never been so excited to spend a small fortune! Off to the ‘shed to wait for Mr Vanos to arrive

 

[Rha]

Never been so excited to spend a small fortune! Off to the ‘shed to wait for Mr Vanos to arrive

Missed this write up some how till now, what a great read. We'll have to call you the alternative parts guru.

 

[GazHyde]

A few pics from the day, generally it's all good in there which is a relief. Mr V can't tell if the VANOS is faulty till he tears it down to refurb it for reuse. Driving home it's definitely a bit smoother and got a bit more go to it. It's had a hesitation on and off from low revs and I'm fairly sure this has fixed that. So a decent investment!

The service is "Vanos and timing chain replacement using all the updated guides, new bolts for the cam gears and a reconditioned solenoid pack. It also comes with a modified oil pump to prevent the exhaust hub tabs cracking. 3 years warranty, once done we expect this to last the life of the engine."

Engine cover off

Rocker cover off, pretty good under there so looks like regularly oil changes as I'd expected from the service history.

Original timing chain

New timing chain, watching how he fits the chain is amazing. It's a closely guarded trade secret he's developed and designed tools to carry out without removing the engine.

Refurbished VANOS unit fitted

Certified

 

[bertiejaffa]

Will have to have a look at my Vanos for that little plaque - I was here when he did my Z3M a couple of months ago but he did my Z4MC in April when I was out on the Scottish run so I never got to see him do his bit... nice chap though isnt he....

 

[GazHyde]

Wobbly knobbly end!

Strange update, but I try and document everything where I can. Since the Brands Track Day last month I'd been noticing a clonk getting worse from the drive train when letting the clutch out. There had always been an almost undetectable - unless you're really listening - noise in the drive train which was less noticeable after the subframe refurb. However clonks always end up clonking more and never fix themselves so we put the old gal up in the air again to have a good investigate. Suffice it to say if you turned the input the clonk was there and we considered that it was the diff refurb and perhaps the input hadn't been torqued down correctly. 45 minutes later the diff was out of the car on the floor and off to our diff-erent diff guy who is less than a mile from the shed. Left it with him to look at when he got a chance and it came back the following week NFF (no fault found). He stripped it down and checked everything, inspected and gave it a full bill of health.

This got us thinking so we grabbed the prop shaft from the corner of the shed it was stored in. Low and behold the knobbly end was knocking and not turning as nicely as you'd expect a CV joint to do. The cause probably won't be known, she's done 129k miles, grease may have got contaminated while off the car for 3 weeks during the refurb, or maybe even dropped/knocked when stored. Totally not anything at all to do with my "unsympathetic" gear changes thank you @Lee . However a Google of the PN and the word failure brings up a multiple threads on the M3 forums of similar issues all solved by replacing the coupling. So I'm going with that, and 100% not my driving!

For once a thank you to BMW as the Const.-veloc. joint wthout knurled bush (#17 below) is a replaceable part on the M and available as a kit from BMW. The kit comprises the "knobbly end", circlip and tube of lube, in stock next day for £262.88 (ouch).

An all to familiar view of my underside...

New CV coupling fitted and suitably bathed in the Castrol Optitemp supplied by BMW. This style of coupling is shared with the E36/46 M3, Z3 and non-M Z4's use a dry CV coupling.

A shot of the input flange on the diff.

We would have test driven it by now but the battery flattened while it was on the ramp. It's now on a conditioner to see if we can save it as it fell below a level our usual battery charger couldn't charge.

This quality unit despite it's claims of high performance (note the use of all capitals to highlight their point) is on the list to be changed in the future. They also use the world calcium twice, so that's a thing! While it's correct for the car, I'd rather change it sooner before it dies completely. Also, because it's flat I've got to reprogram all the window functions to coordinate with the roof *AGAIN*.

Currently got it plugged in to this beefy unit (note their use of the word deluxe, swanky eh?) which we think/hope may keep it going till payday!

 

[Dino D]

‘Totally not anything at all to do with my "unsympathetic" gear changes thank you @Lee ’
@GazHyde don’t feel to bad. he has a go at me about the same thing - said he’s never driven with someone so ‘deft’* with the gear changes as me.
Seems you have taken the cake though as I’ve not broken anything like that

*my correction of word to avoid expletives

 

[GazHyde]

A feeling of deja vu as I get to fit another power steering pump! The second hand M3 pump lasted just under 3k miles and the track day last month pretty much finished it off. This time I ordered a brand new pattern part from Autodoc (holy crap they are slooooow to deliver) as I'm still not willing to invest over £500 with BMW right now. Autodoc supplied this, looks pretty good quality when I received it so in she goes.

Was assisted by @mwpe today and I'm glad I had someone because this simple switch but we had a problem with a slight design change in the pattern one. Took a while to figure but with @Lee on the end of the phone we got through it. Stripped the old one down on the bench and it looks like the bearings had given up, unlike the last one which had failed internally.

First off it's way easier changing the pump from underneath the car, the last one was before we had ramps and did it on the floor from above. Except for the power steering fluid dripping down your arms and on top of your head that is!

Mounted back in place ready for the two lines to be fitted. The black cap is a temporary cover for shipping and that's where the reservoir feeds in to the pump. The white screw cap is where the hydraulic line (banjo connection )to the pump.

As for the problem we had, note the copper nut head that the plastic screw fits in to. This is a threaded insert and it's what the banjo connector is bolted to. If you compare the two threaded inserts next to each other there is a difference of about 1mm across the head, but the threads are the same (the angle doesn't show this very well.

Because of that 1mm difference the banjo bolt wouldn't tighten down on the hydraulic line connector tightly.

So we did the (what seemed) obvious and swapped the inserts over. This decision was taken while the pump was fitted and with limited visibility. We then fitted everything together and the banjo tightened down as expected.

What we didn't know was the design change. We'd discussed the difference in the two inserts when we had them together, and there were subtle differences in the core which you can see below. At the time we couldn't come up with a concrete reason not to carry on - so we did. Again hindsight would have been great at this point.

What we couldn't see on the new pump was that the internal piston (valve may be a better term) was different and included a central pin which enters the central core of the insert. It's a very loose fit as the hydraulic fluid needs to pass by it, however it's a fraction bigger than the originals core.

Top of original piston

Top of pattern piston, you'll notice the slight damage to the pin

So what was the problem you ask? The original insert fully compressed the piston by pressing on the pin, thereby blocking the pump from cycling fluid to the power steering rack. Of course this was all unseen on reassembly. When the car was on the ground the steering was incredibly hard to turn.

Convo with Lee on the phone ensues and we refit the new insert and add a washer to both sides of the hydraulic line on the banjo bolt. This took up the 1mm difference in the insert heads. Now I know what you are all thinking - you idiot! You should have a washer on both sides of the banjo bolt! OMG! Realoem confirms it should have two washers.

HOWEVER: I'll type this slowly for you. When I removed what I assumed to be the original pump to replace it last time, there was only one washer removed so it was refitted as per how it came off. I'm now wondering "someone's been here before" and didn't replace both. Not the first time I've found stuff on this car that isn't exactly as it should be. Again, my bad for not double checking with realoem, I'll try harder next time!

Neatly sandwiched between two washers, luckily we had a spare from another car.

She's ready now for another track day on Wednesday!

 

[mwpe]

Glad it is fixed Gaz, sorry I had to leave before it was finished but I always thought it was someting to do with that union, the lack of crush washers didn't seem right.

 

[t-tony]

There's always 2 on a "banjo" union.

Tony.

 

[Althulas]

At least you got there in the end and good documentation for others.

 

[Ianmc]

Reads like a recommendation for OEM parts if affordable.

 

[GazHyde]

Reads like a recommendation for OEM parts if affordable.

Totally agree with you on that, but when you are 6.5k in to a project and you are only 75% through what you *need* to do before you can get to what you *want* to do... Compromises have to come somewhere, this one luckily only got me with my time which is cheap!

 

[GazHyde]

Oil service (129378)

In the last 12 months of ownership this darned thing has had all the big stuff done to it. I think it's probably due an Inspection 2, which when I view the list of what that entails has mostly been done. The only thing remaining from the next service due is an oil/filter change, cabin filter and valve clearances. I've already refreshed everything else, or it's been done by RBM Hampshire or Mr Vanos. The car has had 2 track days in since the oil was changed with the bearing shells at 123k, so it's done 6k since.

My plan is to do the oil/filter change myself and get the valve clearances checked separately by RBM later in the year. Then it's had pretty much everything you can list that a Z4M needs done.

When Mr Vanos was down he said to use Titan Fuchs (whatever Opie supplies) and move to 5k mile oil change intervals, so that was the plan. Opie didn't have it in stock but I bought 6 litres of Fuchs Titan Race Pro S 10W60 Fully Synthetic Engine Oil (capacity is 5.5 litres on the S54B32). Also ordered a Bosch P9264 filter which includes new seals.

Service reset is carried out through a sequence of button pressing while turning the key. All ready for the next track day on Wednesday!

 

[Rha]

Certainly done some work recently Gaz on that "M" and I know it's done 129 but it scares me to see what you put right/ improved and the cost. Proves to me that I couldn't afford to run one even if I found one at the right price. I'll stick to basic maintenance and change the look of my e85 roadie, that'll keep me occupied till they decide I'm no longer fit to hold a licence plus the wife really doesn't mind riding in it. Do miss the coupe though, but at least I've owned one for a little while. The "M" I'm afraid was never to be for me and with 75 coming up in March it's about time I settled down and appreciated what I have.( well unless we sell up of course)

 

[GazHyde]

So, that's a thing....

Also 6,823 glorious miles at an average 22mpg