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.

Continued below...

 

[iiNNeX]

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 8)

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.

Then I 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.

 

[iiNNeX]

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

** That's progress up to date** sorry if some of it doesnt make sense, I copied it over from a different forum

 

[iiNNeX]

And yet another update

Decided it was finally time to remove that crappy Clutch Delay Valve that makes you look like you can't drive a manual properly...

Here is some pics of the process, including one of the valve showing how tiny the hole the fluid has to move through is:

While at it I also did the clutch stop mod.

Initially, it didn't fit properly (the thread was 0.3mm too small) but some tape fixed that. It is not coming out anytime soon but if it does, I have another idea how to secure it better.

Then it was time to fit the final my ZHP knob which I must say is a HUGE improvement in feel and keeps that OEM+ look for those that are after this sort of thing

Quick comparison of size difference:

Then proceeded to fit a few missing/broken trim pieces:

And last but not least, a sneak preview of the upcoming brake overhaul. I will list everything out in detail as I take on the work.

That will be it for a while as I am off on holiday for a few weeks. Wheels are also now done and back from Lepsons, they look absolutely immaculate and I love them, but pictures will have to wait

Thanks for reading.

 

[mwpe]

Nice write up, it looks like the car has found a good home. Might see you around Camberley sometime.

 

[iiNNeX]

Nice write up, it looks like the car has found a good home. Might see you around Camberley sometime.

Thank you mwpe, she is getting there, slowly but surely. Hope to see you around sometime

 

[Ian_C]

Nice work

 

[Althulas]

The pears soap worked a treat in those head rests, nice progress.

 

[andyglym]

Excellent write-up, coming along nicely

 

[iiNNeX]

Update time.

So it was finally about time to get my ass in gear and sort out the sub-par brakes.

Starting off with removing the old and crusty

The original plan was to buy a kit and rebuild these myself, but I decided to just pay for the privilege. These are refurbished BMW/ATE units and they simply want your old ones in return. They come with a very light coat of generic silver paint which I covered over with my Foliatec kit.

And all back on ready for bleeding

Excuse the DIY Jar bleed kit, but it works quite well haha.

Fronts done also

Had to use a single copper washer on each side to remove play

Now going to be bedding them in and have 1 more thing to do before the other wheels go back on.

Even after a short 10 mile drive the car feels miles better than before. I also replaced all my coil packs with Delphi units (as quoted on realoem) as I was getting some weird idle issues. Seems to have sorted it, here's a comparison of the Bosch part vs the Delphi:

To complete the electrical overhaul the last piece of the puzzle was the battery, the one in the car wasn't too bad but it was old and incorrect (AGM) so got a new Banner to replace it with. Sadly the car is missing the little vent valve so I have installed it without for now and have one on order.

Need to speaking to a few bodyshops soon about sorting the front bumper chips/scratches so I can give it a 2 stage paint correction and polish. Ruby black is such a lovely colour in the sun but it needs to be 10/10 in order to really show, otherwise it has this haziness to it, almost brown like.

On another note, if anyone knows any good soft top restoration products, I'd love to hear from you

Thanks for reading

 

[iiNNeX]

So been a month since my last update, got some more progress

Managed to get that grey hose and vent valve for my battery, also installed some foam under the bracket as it was sitting a bit loose and wobbling around. Gave the compartment a clean while at it as well.

Then I got around to updating my Sat Nav software and maps to the latest genuine version I could find, here is what was in the car already:

And the upgrade that followed:

After this, I had to address the scrapes and scratches on the front and rear bumpers. Unfortunately, a polish would not fix this and there was even some paint cracking around some of the rear parking sensors, so removal and full respray it is. Here is some of the damage:

Which left her looking a little naked:

Front V-brace thing had to come off as paint was flaking and basically falling apart:

Quick rub down later:

Then primer and 2 coats of satin black:

The undertray was looking a little worse for wear, so I thought I'd give it a clean and give it to my old man to re-attach the broken clip locations (they were just dangling inside when we removed it, someone must have over tightened them with a power tool or something).

Meanwhile, I took the headlights off and disassembled them to clean the cloudy projectors and replace all bulbs with OSRAM units.

After refitting everything, I gave them a 4 stage polish and UV coating to protect them going forward:

Then this came through the post:

I thought about refurbing the old one but then things escalated...

- 2x Magneti Marelli fog lights
- genuine bonnet bmw badge
- new fittings (screws and clips all around)
- the new trim piece you see above of course
- polished bumper reflectors


Continued...

 

[iiNNeX]

Continued...

Brace then went back on

And the bumper is complete (ignore misted headlamps, after turning them on that cleared within minutes). Put the car on my personal plate as well, downside is it now looks even older lol. Also removed the plinth

Then it was time to assemble the freshly painted rear bumper, but before that, I had to remove the rear light units, clean them up and change the bulbs in there as well for OSRAM units.

Oh and I almost forgot, the wheels are done! Freshly refurbished to "OEM" spec by Lepsons, expensive to do for split wheels but damn is it worth it... enjoy the shots

Had them coated with Gyeon Q2 Rim as well

More updates to come, need to get wheels on and tracking sorted as I have spacers on their way too.


There is something else too... the car might be up for sale soon... I will explain the reasons in a later post, or perhaps in the sale thread itself, but basically long story short, this was a stop-gap between a bunch of M cars and my first Porsche. The latter I could not do as the example I had found sold and then prices went mad, but I think I might have my eye on something. Also, I have spent far too much on this, considering it was meant to be a car for a few months of fun, but I just couldn't let it sit there in the state it was in, it deserved better. I digress but if anyone is interested in the car before it is officially listed, feel free to PM me for a chat.

SK

 

[iiNNeX]

It's time for another update.

Before I purchased the car I was informed that the rocker cover gasket and oil filter housing gasket were changed, there was however no invoice of this. That said, upon investigation there were no leaks or signs of misting so I accepted it as a done deal.

Fast forward a few thousand miles, I noticed some misting first and then actual dripping down the side of the rocker cover. Once inspected further, it seems that this was coming from the valvetronic motor gasket. Rather than faff about with ordering just a gasket, I thought I might as well do it properly and replace the entire cover, which of course includes a lot more gaskets and a new CCV (as it's integrated for the black top N52 engine).

Here is the leak

Squeezed the Z in the garage and started stripping it at around 6pm

Cover off, looks pretty clean in there

New febi bilstein part

Everything was torqued up to BMW spec

And all done, looks like it just rolled out of the factory! (almost haha). Gave some surounding components a clean too while at it.

Then the next day I took it out of the garage and gave it a clean. You ll notice the cowling and wipers are off, more on that later.

When I bought the car I noticed the wing mirror glass was different, didn't think much of it at first but as I've now had it a while, it became apparent the driver's side was not heated and the passenger side just didn't sit as flush as it should.

So I took them off to see what was what

So the OEM glass looks like it was re-attached at some point?! Or replaced I don't know, but it was definitely not going to heat up with that sticky tape there.

And then the other aftermarket blue glass was heated however it was for an E90, not a Z4. You can tell this by looking at the back as the heating connectors are on the opposite side (and it literally says E90 on the plastic).

So I ordered the correct glass for the car, in a neutral colour (as cool as the blue looks, its a bit of a gimmick) and set about fitting it.

With that out the way, I had one last task to complete for the day and that was to install my new wipers and sort out the squeaky wiper mechanism. While at it, I also removed the cowling, cleaned it up with APC, then IPA, and then treated it with a back-to-black solution, came out pretty good I think (satin finish). Also painted the wiper arms in satin black 2K paint with satin clear coat.

I have also realised that I barely post any pictures of the car actually put together, don't worry though it is being driven I just forget to take them... Here is one with an autumn setting: 8)

And 2 more with a grey/sunset vibe going on:

So as mentioned previously the car will be going up for sale shortly. It was always going to be a stop-gap for me, but I'd say I've done it justice and given it a more than adequate home. Before doing so, it has been booked at a reputable detailing firm to have it paint corrected. I mean it's by no means bad, but after having refreshed the front and rear bumpers, it is the right call to complete the look.

If anyone is interested in the car before it goes to eBay/AT/FB/various forums then feel free to get in touch for a chat.

Thanks for reading

 

[iiNNeX]

Car came back from it's enhancement detail, very pleased with the result.

Sailed through it's MOT yesterday

Also took some fresh pictures for the upcoming sale ad, here are some of my favorites :

 

[Z Victor 1]

You've done a superb job (jobs!) on the car, everything looking great. Just don't ever park it next to mine. My poor car would be so envious.