I finally bought a Z4 - Ownership thread!

[DaveP]

It sounds so much better than my last one. Need to have a poke around in the airbox, but as it stands I don't think I'm going to bother with the cone filter I bought.

Well, I've found the smoking gun.

Looking through the receipts shows that it's had a rear silencer delete done. I need to have a poke around underneath, because it's much less noisy than I'd have expected.

ETA - Nope, it's still there.

[DaveP]

An expensive selection of plastic pieces. Shout out to BMW Park Lane for bloody quick service though.

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[Barty]

An expensive selection of plastic pieces. Shout out to BMW Park Lane for bloody quick service though.

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Nice! Everything to overhaul the shifter linkages? Any chance of a list of part numbers, it would really help since this is something I’d love to undertake as well

[DaveP]

An expensive selection of plastic pieces. Shout out to BMW Park Lane for bloody quick service though.

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Nice! Everything to overhaul the shifter linkages? Any chance of a list of part numbers, it would really help since this is something I’d love to undertake as well

Posted on the bottom of the previous page. I spent a fair bit of time in RealOEM, and they were the only bits I could see that would make an appreciable difference to the quality of the shift.

I guess 100k miles isn't bad for a load of plastic, and I'm really hoping it's going to be noticeably better than the current poor shift. Even though the gearbox oil was replaced last year, I've got a mix of notchy (2->3 being worst, and one I'll use a lot on track) and sloppy (4 and 6 both sort of 'flop' into gear) changes that need to go away. The plastic collar is almost certainly going to need replacing, so I figured he may as well do the lot while he's in there.

I've ordered a lovely billet aluminium shift knob too, after comparing weights of the ZHP and OEM knobs. The ZHP may be shorter, but the extra weight is barely worth writing home about. The knob is for an R53 Mini (my old car), but a quick bit of research suggests that it should fit the Z4 just fine.

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Anyway, car dropped off this morning, and hoping to pick up on Tuesday to give me time to get the alignment done before Friday at Snetterton.

[DaveP]

New tyres were fitted to my 107s yesterday, and ATS Euromaster were surprisingly competent. I guess having bare wheels meant that they weren't able to upsell me on any 'additional services' I didn't need.

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I'm very much looking forward to getting the 17s on (pictured here with the scrap ditchfinders) to improve the ride. They will go in for a refurb at some point soon to fix some of the kerbing, but I didn't want to bother getting that done only to hand it over to ATS and watch them scratch the hell out of them. New centre caps waiting to go on too.

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[DaveP]

Well, I'm glad I asked the mechanic to go around and check the suspension while he was underneath the car. Apparently one of the balljoint nuts was barely hand-tight...

That could have been absolutely catastrophic on track.

[DaveP]

Looks like the RTABs will need doing at some point soon, although not urgent. Kind of expected this, based on previous BMW ownership.

Gut is to just go with a set of Lemforders for £70. Has anyone bothered with poly bushes here?

[LemonConnoisseur]

Go for polybushes, there’s no real downside to them imo, and they’re a s**t load easier to fit, so you should save on labour!

[DaveP]

Go for polybushes, there’s no real downside to them imo, and they’re a s**t load easier to fit, so you should save on labour!

Any brand in particular? I've used Powerflex in the past and found them fine. Should I consider loose bushes, or look at the brackets with bushes pre-installed?

[LemonConnoisseur]

Any brand in particular? I've used Powerflex in the past and found them fine. Should I consider loose bushes, or look at the brackets with bushes pre-installed?

Powerflex is what I would recommend. For the RTAB, there’s no real difference between opting for purple or black, as I really don’t see the increase in NVH that you get when replacing other bushes in the car.

Just buy the loose bushes, your mechanic will likely need to burn out the old one (this is what I did about 3 weeks ago) and that takes the longest. Installing the new bush is literally a 5 minute job!

[DaveP]

The car is back, the brakes feel excellent (I really rate ds2500 pads), and the shifter is ... less rubbish. Not the transformation I'd hoped for, but an improvement.

The biggest win this week was getting the 17s fitted. I can't quite believe how much difference they've made to the way the car rides on the bumpy country lanes around me. I hoped it would improve things, but I didn't expect it to be this good!

I'd wholeheartedly recommend anyone who properly uses their car on rubbish British country roads to consider it.

All that's left for this week is to fit my new knob, get the alignment done tomorrow morning, and then figure out where I fit the GoPro (currently favouring the rollover bar). It's currently looking like a wet day at Snetterton, so perhaps not the ideal way to do my first trackday in a rwd car...

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[DaveP]

Nice knob. No, really. It's actually very nice.

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The stock gearknob is embarrassingly rubbish. It looks like it's been lifted from a base-spec 5-series. I checked the weight, and looked at the ZHP to see if it would be a significant improvement, and was a bit underwhelmed by the weight difference. So I started looking at Storm Motorwerks stuff, and was just about to buy one when I spotted this listing on Ebay. https://www.ebay.co.uk/itm/204268943335

Knowing that the R53 Mini and Z4 have push-fit knobs, I took a gamble and assumed that BMW had used the same diameter shaft. Turns out I was right. The knob fits with 3x 2.5mm allen grub screws, and it is both significantly shorter and heavier than the stock item (as well as being heavier than the ZHP). I'd say this has made more of a difference than the bushes I replaced, to be honest. Highly recommended.

Pro-tip: It looks like the knob is out of stock as I'm posting this, but if you "Watch" the item on Ebay you may get (as I did) a reduced offer from the seller. At £40 it's a ridiculous bargain.

Other than that, the alignment was done yesterday morning. As expected, it was bloody miles out to start with.

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I ended up at roughly 1.5 camber each side at the front, and 2.5 at the back. I elected to have zero toe both front and rear to see how it made the car feel. Annoyingly the garage did spot a small tear in one of the front topmounts and I spotted a little weep from the left-hand engine mount while I was under the car, so they will be sorted as soon as I get the chance.

So off to Snetterton I go tomorrow, and the weather is predicted to be absolutely bloody minging. Even though I've done a lot of trackdays in the past (including the Ring), I've never driven any of my previous RWD cars on track. It might prove to be a bit of a baptism of fire, but I'm keen to find out. I think I'm going to try the first few laps with DTC enabled (short press on the TC button), to see how it behaves and whether there's enough control over the rear end. Going to look at GoPro mounting later today, and might share some footage if I can find a decent home for it (looking between the roll hoops at the moment).

[DaveP]

Well, that was fun!

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As is the case with every trackday, particularly the first one with a new car, you tend to use them as opportunities to find out where the weak links are. The weather was appalling, with rivers running down the pitlane at times (I'm thankful I paid for a garage!), so I wasn't really going to learn much about the limitations of the chassis. That said, the grip from the new tyres was absolutely ridiculous even in deluge conditions, so I'm really pleased with that. My biggest fail was not checking for a towing eye, which is mandatory on track to make recovery easier (and ensure the track is closed for as little time as possible). Thankfully a neighbouring garage was full of 'Clubsport-spec' E92 M3s, and one of them had a spare towing eye that he was happy to lend me for the day.

Reliability was thankfully not an issue either. Nothing broke, and the car ran faultlessly until 3.30pm when I felt a slight hesitation when getting on the power out of a corner. Scanning the codes with my trusty Creator C310 showed two really confusing outputs, and there were no lights on the dashboard either. I was expecting a misfire on one cylinder to tell me that the underbonnet heat had killed a coil pack (I can't find any receipts for them, so they must be due a failure), but not so.

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The above seem very uncommon codes, and there's very little coming back when I Google for them. I reset them, called it a day for driving, and left the bonnet open to cool while I went off and did a little wet spectating. The car drove home faultlessly, and the codes didn't reappear. I'm going to replace the thermostat and water temp sensor because I can't find any receipts for either.

Current To Do list now looks like:
- Replace leaky engine mount(s)
- Replace front topmount bushes
- Replace front RTABs
- Swap in braided brake hoses (pads went well, but pedal feel wasn't great)
- Buy a spare coil pack
- Buy a towing eye
- Replace thermostat and temp sensor (along with coolant flush and waterless coolant)

The Discovery is going in for a service, an MOT and a few little niggles to be fixed before its driven to Islay in May, and the Volvo is off for its first service in our ownership shortly. Spending on the Z4 can potentially wait until next month!

[DaveP]

Holy thread resurrection, Batman!

I had been keeping a thread going on another forum, but have decided to stop posting there as it became a very odd and toxic place!

It's been 11 months since my last post here, and much has happened. I'm not going to bore you all to tears by recanting everything in excruciating detail, but needless to say that the Z4 has been very busy!

Highlights include:
- A brilliant trackday with a group of friends at Cadwell Park last year
- A 2,000-mile roadtrip around Europe (7 countries in 9 days), including a visit to the Ring
- Lots of wonderful top-down driving on the lanes near me

The Z4 has had a fair bit of fettling since the last update here.
- New engine mounts and LCABs
- Braided hoses all round, and new hard brake lines to the rear
- BC Racing coilovers installed (fabulous!), and a much better alignment done
- A set of Style 290s fitted (thanks to Mr Tidy of this parish)
- A pair of half-leather, heated Sport seats fitted
- Replacement LCM, after some weirdness
- New inner and outer track rods, to cure wandering alignment

All of which brings us up to date, and this is how the (filthy) car is sitting.

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[DaveP]

I've been lucky enough to bag a trackday at the Nurburgring later this year. They are pretty rare, moreso when run by UK-based companies which means that third-party insurance is possible (a prerequisite for me!). I'll be towing the Z4 over for two full days of driving on a closed Ring in September, which I'm very excited about. As a consequence, everything I'll do this year is largely in preparation for that.

I'm heading over with my group of trackday friends next month to get my eye in again over a weekend. With the track open for two days it should mean that, even with the added madness of tourist sessions, I'll be able to get quite a few laps under my belt. So before that, it's time for a little titivation.

Now that the coilovers (with their solid topmounts) are on, it's highlighted sloppiness in a few areas of the suspension. The OEM LCABs I installed last year are deflecting on heavily cambered roads, so it's time to swap them out for poly bushed alternatives. The RTABs didn't look too clever when the coilovers went on, so they are getting the poly treatment too.

I'm also going to do a big cooling system overhaul. The car didn't come with a load of history, so I feel like this is good 'preventative maintenance'. I figured I may as well refresh the whole rotating assembly on that belt, so I'm swapping in:
- Nissens radiator
- OEM expansion tank
- Meyle water pump, with steel impeller
- Mahle thermostat
- OEM idler pulleys
- Febi tensioner and pulley
- New Conti belt

Not very exciting stuff. But missing out on track time because of a broken car isn't very exciting either.