My E85 Z4 2.5Si Journal

[iiNNeX]

Welcome to my humble journal of my recently acquired Z4. The purpose of this thread is to document its progress and hopefully help people along the way who are looking to do the same. I am a sucker for clean OEM+ builds so that will most likely be the theme here. This is not my first BMW, in the past I have been lucky enough to own 2x E46 M3s, E60 535d and a F87 M2 LCI, however this is my first Z4 so bare with me as I figure things out along the way.

I found the car on an M3 forum and it was priced extremely well for something with such spec and reasonably low mileage (73,900). It is a 2007 (57 plate) facelift Z4 with 2.5Si configuration in Sport trim. It has then been labelled as an Individual due to it's Ruby Black paintwork and Extended Champagne Nappa leather which covers a lot of areas in the interior that are normally plastic. Options wise It has the following:




After seeing the car in person I left a deposit and went to collect it the next day.

First car park photo after a quick trip to the petrol station


Quick coffee run to celebrate the purchase


And then that was the extent of my photos for the day.

The next day I set about giving it a clean inside and out in order to better judge its condition and what I need to do.


First thing that had to go was the bronze/carbon-look stubby.


Replaced with OEM looking rubber one.


No photos during the cleaning process but I used Bilt Hamber products for Pre-Wash snowfoam, wheel cleaner, shampoo and quick detailer after.

End result here:











Overall it's not too shabby but there are definitely areas that need addressing, some of which I was already informed of during the sale and others that popped up on closer inspection AFTER I purchased the car... just as they do right? haha

The wheels are probably the worst offender:




They have heavy corrosion and paint has mostly peeled off on the inside of the barrel. They hold air just fine and look OK from about 5 metres away but there is no way they are staying like this. Also, the brake calipers could use a lick of paint upon first glance, however, an overhaul is on the cards after a closer inspection.

The car was also at RBM having a new roof motor installed and a quick glance at the boot confirms this:




Continued in the next post...

[iiNNeX]

The following day I took the car out for a decent drive through some back roads and a lengthy motorway journey. This confirmed a couple of areas that need addressing, so I ll start with the most obvious.

1. Water splashing noises from behind the driver's seat
- This is probably not uncommon or unheard of for you Roadster owners but it did give me quite a scare. Upon investigation it turned out to be blocked drainage holes on both sides (typical?!). It was filled with gunk, rotten leaves and whatever else grows in between those. Used a lot of APC and a few hot water flushes to remove that.

A hose, a long stick and 10 minutes later, it was all free-flowing again.




And these b*astards can go straight in the bin.


BMW over the years has had some questionable design ideas, this is definitely one of them.

2. Next up were the spongy/squeaky brakes
- So basically after a short drive the brakes would start to squeak quite bad (almost as if they had race pads lol) and the handbrake was pretty much non-existant for 5-6 teeth and then suddenly bit hard. I decided to strip things down and investigate the situation before ordering any new parts.

So then, wheel off and arch guard removed.


Covered in APC and agitated with a brush, then pressure washed after letting it soak up for a few minutes.


Gave the hub a good brush with a drill attachment and removing the disk revealed what appear to be almost new OEM brake shoes.


I sanded them down just a tiny bit and proceeded to address the inside of the brake disc, which explained the sub-par biting force.




Gave that a wire wheel and sanding treatment also, much better now.


Arch guard also received a clean while at it.




They were then refitted and handbrake tested, which was much much better than before. Although it does actually need adjustment to bring it up to OEM spec, that will be done at a later stage as I have other plans for the brakes. I did the above procedure on all 4 sides.

I forgot to mention that I managed to snag a set of 16s with tyres for £80, so that gives me the opportunity to remove the 108s and figure out what to do with them.

Here she is in monster truck mode.


3. The last immediate issue was the engine running a tad lumpy at times.
- It would start just fine but sometimes would run a bit odd on idle and perhaps not pull as clean every single run.

Checking the plugs explained that problem...




A new set of NGK ILZFR6D11 (1208) Iridium plugs were then swiftly installed.


While at it I then also replaced the air filter with a genuine item.


Airbox was a tad filthy but nothing a bit of APC and elbow grease couldn't sort.


Had a look at the throttle body and that was sparkling so good news there.


And that was the work around the engine bay complete.


Yes, it's filthy and I will be getting to that, but most importantly no leaks of any sort. The car has had the rocker cover gasket changed previously so that saves me another job

Moving onto the interior, the removal of the cabin filter released a bunch of dead leaves, which is always great to see lol


The old one wasn't bad but still a few years old, new carbon OEM filter in place now


Upon collecting the car from the seller I also noticed the plastic housing around the rain sensor was missing.


Got a new set from BMW and set about fitting it.




Much better now.

While focusing in the interior, I was happy to see that the car came with cup holders from factory. Sadly they were basically shot, one wouldn't open at all and the other was broken, so both were swiftly removed and new ones on order from BMW.

This is what remains of them now.


And this is now an "Individual cooling system" that my car has for the meantime


And lastly I wanted to stream music via my phone but couldn't use the Aux system the car had AND charge at the same time (ffs Apple why single connector?!). Also I want less cables cluttering the interior, so a BT dongle by Bluemusic was purchased and fitted in place. It replaces the 6cd changer which nobody uses anyway, but still allows you to play a CD through the headunit itself.

Here it is.


Neatly tucked away as if it was OEM.



And that is all the updates I have so far. I have ordered many more parts and will document the works as they come. Thanks for reading!

SK

[enuff_zed]

Some good work going on there, well done.
Interesting that you went to BMW for cup holders. Imagine that's quite pricey?
I picked up a pair on Amazon, Chinese copies but indistinguishable from the real deal, at less than the cost of one original.

I would also say, from personal experience, that your collection of leaves from the cabin filter change is much less than I would have expected, so hopefully that's been changed a few times before.

[iiNNeX]

Some good work going on there, well done.
Interesting that you went to BMW for cup holders. Imagine that's quite pricey?
I picked up a pair on Amazon, Chinese copies but indistinguishable from the real deal, at less than the cost of one original.

I would also say, from personal experience, that your collection of leaves from the cabin filter change is much less than I would have expected, so hopefully that's been changed a few times before.

Thank you bud!
I am a sucker for OEM so try and get that unless it is uneconomical to replace. The cup holders are around £46 each without the faceplates (which are £5 each I think) but that is before any discount. I can get anywhere between 7 to 15% off discount depending on the part from some of my most frequent dealerships so it's not that bad.

As for the leaves, there was a lot more but they were clogged inside the filter itself. It has definitely been changed but not that recently.

[Mr Tidy]

It looks like you are making some good progress there.

108s are definitely a challenge! While they look good, they always suffer from blistering over time. That's why I swapped to a different style on my previous Coupe and sold the 108s while they were still in good nick.

If you do decide to get them refurbed there is a good firm called "My Alloys" in Basingstoke who Ross at RBM uses. They did a great job of my 224s for £60+VAT per wheel, but 108s would undoubtedly cost more as they need splitting for a proper job.

[iiNNeX]

It looks like you are making some good progress there.

108s are definitely a challenge! While they look good, they always suffer from blistering over time. That's why I swapped to a different style on my previous Coupe and sold the 108s while they were still in good nick.

If you do decide to get them refurbed there is a good firm called "My Alloys" in Basingstoke who Ross at RBM uses. They did a great job of my 224s for £60+VAT per wheel, but 108s would undoubtedly cost more as they need splitting for a proper job.

Thank you Tidy, she will get there soon enough.

Regarding the wheels, the 108s are a timeless design in my opinion and suit the Z4 very well. So there is no way they are not going back on, but they definitely won't be diamond cut, which will eliminate that worry

I have been to Lepsons and they had a look at them and provided a quote, also a few other places more local to me, but ultimately this is going to be in the realm of £650-£700 for the set to be done properly. The price would be a lot lower if I can split them, which is what I will be giving a go shortly, just waiting for some tools to arrive

[Timmyboybunter]

Love a good journal great start.

Some of the common irritations ticked off the list already!

[iiNNeX]

Love a good journal great start.

Some of the common irritations ticked off the list already!

Thank you bud, I enjoy keeping track of its progress.

Speaking of which, she's had a little more love recently.

Had this lot delivered a couple of days ago.

Castrol Edge 5W-30 M engine oil
Genuine BMW Oil filter
Redline MTL Gear oil
Castrol Transmax 75W-90 Differential oil

Was tempted to do them on the drive but gave my friend who owns a garage a call and they let me use the ramp after hours.


Starting off with the engine oil, it wasn't pretty...






Then moving to the gearbox oil which funnily enough states "lifetime" on the label. Marketing BS...






No metallic bits on the magnetic plug which is good.


And lastly, the diff oil which was a little dirtier.





And that's all the fluids done. I plan to do a coolant flush at some point in the near future as well.

Next up, after calling various places for quotes to refurb my 108 2 piece wheels, I got fed up with being told all the scare stories about people stripping bolts due to the age of the wheels and how much more money it would cost if they do (£15+VAT per thread...) so I decided to split them myself. How hard could it be?

The reality is, it's not hard. It just takes patience, the right tools and some sort of beverage to keep you company.

First I had the tyres removed.


I then took the wheels back home and soaked all the bolt heads in WD40 and left them overnight in the garage. Next morning was the make it or break it day.

These are the tools I used

- 8mm Spline 12 point socket bit (100mm but you can use shorter)
- WD40
- Hammer wrapped in some electrical tape
- Heat gun

So process goes like this, soak up with WD40


Then apply heat as below, this allows the alloy to expand thus releasing its grip on the titanium bolt


After about 60-90 seconds of heat application, you can start to undo the bolt (SLOWLY!). I recommend undoing a few threads then spraying more WD40 as you undo the rest of it.

After all the bolts are out, gently tap the centre of the wheel with a hammer (wrapped mine in tape to ensure no damage is done to the alloy) and it should come apart.


And voila


Didn't take a pic of all 4 apart but you get the idea.

Next up was an hour's drive to Lepsons in Gillingham and I should have them back in 7-10 days or so.


Had some more BMW boxes turn up today so will update in due time.

[JamesClements]

Great thread Be interested to see what you go for on brake upgrades have been considering doing something myself for a while the standard calipers look a little small behind 19's and mine are due a refurb soon anyway.

Cheers

James

[bigwinn]

All over this thread- great work bud!

Subscribed.

Stuart

[iiNNeX]

Great thread Be interested to see what you go for on brake upgrades have been considering doing something myself for a while the standard calipers look a little small behind 19's and mine are due a refurb soon anyway.

Cheers

James

Thank you James, brake wise I am currently accumulating parts but will be sticking with stock calipers, just giving them a new life. I was thinking about adapting the M sport calipers off a M140i or similar but I believe the car will have enough braking power given it's power output after a full refresh. If I still find it lacking then, I will consider the above option or even the brembos from a Clio/Megane RS usually come up at a good price.

All over this thread- great work bud!

Subscribed.

Stuart

Thank you for the kind words

The Z got a little more love today.

One part of the leather that was really letting the interior down was the little hoops behind the seats. They are in good condition but extremely dirty, and it was the type of dirt a quick glance over with interior cleaner would not remove.

So I set to work with the following:


1 slightly damp micro fibre towel
1 dry micro fibre towel
Pears Soap due to its amazing removal of oil/grime properties
A soft detailing brush (can use more abrasive brushes depending on grime level)
Some hot water



I mean ok they are probably not as bad as some, but being such a light interior colour it shows up a lot worse in person than it does on pictures. Anywho, the process for cleaning these was application of pears soap on brush (using hot water to lube it up) and then agitating into the leather for around 2-3 minutes. Then letting it settle for another 5 minutes after which you use the damp towel to wipe off the dirty. Repeat this process until all dirt is removed, then use the dry towel with a leather conditioner to preserve the look and feel.

Here is an after shot


And the other side





I plan on doing the entire interior like this as well as polishing the piano black trim but want to sort a few other things first.

Another thing I noticed was moisture inside the driver's headlight. There were little droplets at the bottom of the light which was odd, and upon investigation, it would appear that the headlamp cover and gasket were missing...ffs


Another BMW express mail later and it was rectified.





Oh and my cupholders finally came, so it was great to install those however I am unsure of how robust their design actually is





That's that for now, car is going on a 400 mile trip tomorrow so let's see how it performs

[jamie_z4]

great thread mate. Ive also picked up a very simmlar Z4 recently (My 11th Z4!) Its a midnight blue (individual) with champagne nappa, just not extended like yours, but has the champagne nappa dash trim in place of the piano.

Look forward to the progress

[zriha]

Wow, I will keep on your progress mate! Wonderful job. I just wanted to ask, I am still between oils. I switched from Motul 8100 X-cess 5W30 to 5W40 Shell Helix Ultra as Shell has the BMW LL01 mark, but now I don't know if I made a mistake. What do you reckon, 5W30 or 5W40? I live in Croatia, so we have warm summers and cold winters (but I don't drive Z4 in winter). Thanks!

[iiNNeX]

great thread mate. Ive also picked up a very simmlar Z4 recently (My 11th Z4!) Its a midnight blue (individual) with champagne nappa, just not extended like yours, but has the champagne nappa dash trim in place of the piano.

Look forward to the progress

Thank you mate, 11th Z4 wow! To be totally honest I am already considering a jump to a Z4MR, especially after having 2 E46 M3s I really do miss that S54 induction noise. I know prices are creeping up but they are not quite unattainable just yet.

Issue is, finding one as well specced as this car will be difficult imo. Colour combo plays a big part in my decision making, as well as overall condition and factory spec.

You got any plans for your latest car?

Wow, I will keep on your progress mate! Wonderful job. I just wanted to ask, I am still between oils. I switched from Motul 8100 X-cess 5W30 to 5W40 Shell Helix Ultra as Shell has the BMW LL01 mark, but now I don't know if I made a mistake. What do you reckon, 5W30 or 5W40? I live in Croatia, so we have warm summers and cold winters (but I don't drive Z4 in winter). Thanks!

Hey man, thanks for the kind words. I used the Castrol recommended oil for BMW which is Castrol Edge 5W-30 M (don't get the LL marked one as that is no longer BMW LL04 compliant). That said I am sure it will run fine on any good quality 5W-30 or 5W-40 oil. I will be trying Millers next and see if that makes any difference given its higher price point.

[zriha]

Hey man, thanks for the kind words. I used the Castrol recommended oil for BMW which is Castrol Edge 5W-30 M (don't get the LL marked one as that is no longer BMW LL04 compliant). That said I am sure it will run fine on any good quality 5W-30 or 5W-40 oil. I will be trying Millers next and see if that makes any difference given its higher price point.

Thanks for the comprehensive reply. I think, I made a mistake, as 5W-30 is thicker than 5W-40, which shows in oil consumption also. So next oil change, I will go also with Castrol 5W-40, or even a Liqui Moly 5W-30, as I see a lot of Germans recommend them on their BMW's.