Montego Blue E86 is Long Gone - Z4MC Diff Rebuild

[Vijay]

Good read this Lucas. Which discs did you go for? I need to replace mine too...

[lucasxdiniz]

Good read this Lucas. Which discs did you go for? I need to replace mine too...

I went with M-Tec drilled and coated. I have been running them since I got the car and they have held up pretty well, I'm surprised the coating still looks so good after so many heat cycles, many to the point that the discs were blue because of how hot they were. I did warp the front discs, but not sure how as I never park the car or hold on the brakes while the brakes are hot.

[Jameszy]

Lately I've come across a few rough running issues. The first one being a hesitation between 2-3k revs when the engine was cold, but once up to temps, if I turned the engine on and off again, issue completely went away. I tracked that down to one of the coils - so I replaced all 6 for good measure. I must say, if didn't have another Z4 a home to swap bits back and forth, this would have been a hard one to track - no errors, not really a misfire, values on INPA were completely within parameters. Just weird.



Then a couple of weeks ago, I started feeling like the power wasn't very linear - some weird spikes in power. Especially around 3-4k revs. And throttle response either a bit too hesitant or too keen and car was a bit jumpy, and sometimes the idle would be all over the place, cold start would shoot up to 2.5krpm randomly. Again, no errors, INPA values all fine, tried adaptations many times, no luck... Started by removing VANOS solenoids, cleaned and tested them, installed them again and problem still persisted. So bought a borescope and went down the intake to check the small DISA. Both DISAs proved to be working perfectly - I even recorded DISA #2 operating.



At this point I was disappointed, as the only other thing left to test was the eccentric shaft sensor. Not easy to get to, and no shortcuts to check it, so would be a matter of just replacing it (+ all the gaskets and bolts). Put DISA #1 and the intake back together, and surprise, surprise the issue is gone. As I took the intake pipes apart, I made sure they were in place and tight, and all seemed to be, but now I can only imagine they weren't and a a small vacuum leak was causing the issues I experienced. Or it's a coincidence and the problem will come back again. But 200 miles later and all seems fine, so we shall see.

Bonus: checked all of my intake valves. Advantages of port injection and good fuel, no carbon build up!

The eccentric shaft sensor bites again! Mine had the same issue, again with no tell-tale signs (not even a CEL). Thankfully it did throw some codes (some german compound noun for eccentric shaft and plausibility). Out of interest did you get any codes on this?

[lucasxdiniz]

The eccentric shaft sensor bites again! Mine had the same issue, again with no tell-tale signs (not even a CEL). Thankfully it did throw some codes (some german compound noun for eccentric shaft and plausibility). Out of interest did you get any codes on this?

As I mentioned in the text, no codes. I also said how the problem went away before I had to check the eccentric shaft sensor. I checked the connector last week, no oil, so it's probably fine.

[Jameszy]

The eccentric shaft sensor bites again! Mine had the same issue, again with no tell-tale signs (not even a CEL). Thankfully it did throw some codes (some german compound noun for eccentric shaft and plausibility). Out of interest did you get any codes on this?

As I mentioned in the text, no codes. I also said how the problem went away before I had to check the eccentric shaft sensor. I checked the connector last week, no oil, so it's probably fine.

Ha sorry mate I do apologise - I got sidetracked and didn't read that final paragraph. Thought you had replaced it. Glad it was fixed without having to go down that route!

Interesting feedback on your yellowstuff pads. I went with the OEM replacements and am not that impressed with the bite, will be looking to replace

[lucasxdiniz]

Ha sorry mate I do apologise - I got sidetracked and didn't read that final paragraph. Thought you had replaced it. Glad it was fixed without having to go down that route!

Interesting feedback on your yellowstuff pads. I went with the OEM replacements and am not that impressed with the bite, will be looking to replace

I don't blame you for not reading my waffle haha!

The bite from YellowStuff is amazing. From cold the bite is already better than OEM, I think. When hot the tyres can't quite keep up with the brakes. They are quite dusty, but ceramic coating your wheels help a lot. They squeal when the pads are hot and you brake lightly.

[lucasxdiniz]

The repairs I did to my seat when I first bought the car lasted a while but after 15k or so, the driver's seat was starting to look shabby again. Furthermore, they never had that nice matt finish of brand new leather... So I got a few quotes to get my seats professionally redyed so it could look as could as it can without re-upholstering them. After getting a few quotes close to 1k, I stopped being a wimp and just decided to do the job myself. £100 kit from furniture clinic and about 10hrs work, here are the results:

The scariest part of the job is removing the original finish of the leather, sanding it down to the bare leather. It feels like you're destroying the seats and causing £1k+ of damage, but I trusted myself and pushed on while Drive to Survive season 3 played in the background.

I tried capturing the process on camera, but with my living room lighting it was impossible to show it well. Here's a photo of the first 10-15min of sanding the driver's seat.



After the first coat of paint in one of the seats backrest, compared to the shiny old finish. Note the difference in shine.



This is after 3-4 coats of paint, and 3 coats of the leather finish (I used a mix of 25% Gloss 75% Matt). None of that ugly shiny leather!



No seats in the car only asks for a thorough interior clean/detail.



Knowing my seats would be mint, I removed the steering wheel and gear knob and made sure to clean them properly and strip them of any oils that the leather absorbed. Also painted my steering wheel trim.





Here's the end result.





This is the only instruction you really need, please don't message me without at least watching this or reading the instructions in the link for the kit. I get question about upholstery too often.

[1536Z4]

If you have a lowered car and are removing the diff, it would be a crime not to install adjustable camber arms while it's easy! I installed DriftWorks' own E46 adjustable camber arms, they are rose jointed and did not add any noticeable NHV to the cabin

Hi Lucas

Can you give an update on the camber arms . How are they lasting and would you buy them again or would you choose another make .

Is there anything you have changed that you now wished you hadn`t ?

Thanks

[lucasxdiniz]

If you have a lowered car and are removing the diff, it would be a crime not to install adjustable camber arms while it's easy! I installed DriftWorks' own E46 adjustable camber arms, they are rose jointed and did not add any noticeable NHV to the cabin

Hi Lucas

Can you give an update on the camber arms . How are they lasting and would you buy them again or would you choose another make .

Is there anything you have changed that you now wished you hadn`t ?

Thanks

10k miles, no problem. Would buy again, no need for other brands - these do the job.

[1536Z4]

10k miles, no problem. Would buy again, no need for other brands - these do the job.

That`s good to know .

Thanks again

[lucasxdiniz]

[DaveD]

Not sure how I’ve missed this thread but a great read - well done on all the work you’ve put in! Some big and brave calls you’ve made over the last two years!

Really interested in your views on the AFE intake - how is it holding up and have you had any issues with MAF faults? How different would you describe the sound in the cabin vs the sound generator? Videos never really do it justice don’t they. Also, can I ask where you got your most recent exhaust work done? I want to remove my mid resonator and get my Eisenmann race welded on rather than clamped. Always good to have a recommendation for that sort of work.

Cheers

D

[lucasxdiniz]

Not sure how I’ve missed this thread but a great read - well done on all the work you’ve put in! Some big and brave calls you’ve made over the last two years!

Really interested in your views on the AFE intake - how is it holding up and have you had any issues with MAF faults? How different would you describe the sound in the cabin vs the sound generator? Videos never really do it justice don’t they. Also, can I ask where you got your most recent exhaust work done? I want to remove my mid resonator and get my Eisenmann race welded on rather than clamped. Always good to have a recommendation for that sort of work.

Cheers

D

Thank you!

I still love the AFe Intake, it's a glorious sound! No issues with the intake itself, it's holding up just fine and cleaning the filter is fairly straight forward. I did have a problem with my MAF (nothing that threw codes though) where the power curve seemed a bit peaky at times and after cleaning the MAF it went away. No oil residue on the MAF, so could have been age as my car is over 100k now on the stock MAF. If you're worried about this, then I'd suggest get the dry medium filter (slightly less free-flowing.

edit: Style Dynamics in High Wycombe did my exhaust work. They've done a friend's Z4 as well and they've proven to be quite good.

[DaveD]

Thanks Lucas, good to hear on both counts! Need to start saving the pennies again

[Weston Matt]

Hi Lucas,

How are you finding you BC suspension? Thinking of changing mine when I do all my brakes and bushes over the winter

Cheers
Matt