Like your attitude to all this Andy - enjoy reading your posts 
Project 2006 Z4 - restoration (Enjoy!)
- Thread starter andyfanshawe
- Start date
Re clutch, yes they are self adjusting. I'm about to do mine too. Not gone but peddle is high and she's on 84k now. Remember to inspect the DMF too. I've just bought a new one and will replace as I think mine is probably worn and to be honest putting a new one is piece of mind for me.
EdButler said:I would say that a P0402 is most likely an O2 sensor rather than the CAT itself. Its certainly cheaper to swap out the O2 sensor!
Alternatively, swap the Bank1 and Bank2 post-cat O2 sensors and see if the code moves to Bank2.
Good thread btw
Hi EdButler.
I assume you mean P0420. Nothing gets "swapped" without proving it 100%. All 4 sensors need scoping as its being driven. No room for guesses. Short term fuel trim and long term fuel trim are down near 0. Even when the P0420 code appears. So it is highly likely (but not 100%) that the CAT is struggling.
Interestingly, on live data with Verus, Maxidas and a small hand held one, the info for O2 sensor 1, bank 1 and O2 sensor 1, bank 2 are not visible. Only the bank 2 (post cats) are available to view live data on.
There is a beautiful oxygen storage test you can do with an oscilloscope to accurately determine if the CAT is really at fault. I will endeavor to photograph the procedure for those who have access to a scope.
Swapping post cat sensors over is a good idea!
My workshop is busy, so will have to squeeze it in when I can. Customers cars take priority though :-(
And, there is a product called CATACLEAN that has amazing reviews. Be interesting to scope the post cat sensors before treatment, and after treatment. And compare waveforms. In fact, I will do it for fun!
Andy.
Look at the state of this!
Replaced by this
From bmw_direct on ebay for £60.
Andy.
Replaced by this
From bmw_direct on ebay for £60.
Andy.
Common problem - see you've gone clear
benneyboy1
Member
Hi Andyfanshaw just want to say great project and great posts I am really enjoying your updates and the care you are putting into your restoration. I have a few questions for you as I am a keen diy enthusiast and would love to have your level of knowledge and experience.
1) What did you clean the pistons/shoe holders with?
2) What did you clean the rusty hub flanges with?
3) What type of paint did you use to paint the pistons/shoeholders with?
4) I note you have cleaned the hood with the autoglym products did you do anything else to get the hood colour looking so black again. I have used the same products on mine (just once) but my hood didnt come up as dark as yours.
Keep up the great work and thanks in advance.
I live in south derbyshire so would be keen to pop in and say hello one day when you are working on the Z4. I have a 2008 2.5 SE complete with LPG conversion you would be more than welcome to have a look around my car which I have only owned for 4 months and I can talk you through what issues I have identified so you can check them out on yours. Are you likely to be in your workshop this coming bank holiday weekend?
Regards
benneyboy1
1) What did you clean the pistons/shoe holders with?
2) What did you clean the rusty hub flanges with?
3) What type of paint did you use to paint the pistons/shoeholders with?
4) I note you have cleaned the hood with the autoglym products did you do anything else to get the hood colour looking so black again. I have used the same products on mine (just once) but my hood didnt come up as dark as yours.
Keep up the great work and thanks in advance.
I live in south derbyshire so would be keen to pop in and say hello one day when you are working on the Z4. I have a 2008 2.5 SE complete with LPG conversion you would be more than welcome to have a look around my car which I have only owned for 4 months and I can talk you through what issues I have identified so you can check them out on yours. Are you likely to be in your workshop this coming bank holiday weekend?
Regards
benneyboy1
Hi benneyboy.
Thanks for your questions.
I strip down the calipers completely and degrease them in a bucket of shower gel and hot water! Works well and kind to the hands! And cheap. I then stick it in my vice and use an electric drill with these black nylon wheels stuck in the end. Works for hub flanges also. Amazing black abrasive wheels they are.
And i use a carbide burr on a die grinder to get into the nooks and crannies.
Loads of patience needed, and take your time.
Degrease again and panel wipe.
I use 2 different methods to paint them.
If I have plenty of time, I spary a 1K etch primer on like this
Then spray with a white primer from anywhere really! Normal aerosol.
Then spray a few light coats of red smoothrite
And leave to dry for a few days and then reassemble everything.
The other method is a lot quicker.
Derust as above and degrease, then spray with HYCOTE red caliper paint. Couple of coats.
Dries damn quick. Then reassemble.
The softtop was done with the stuff only. Following the instructions. Nothing special.
Hope this helps.
You are always welcome to call in anytime. Not sure when Ill be working on the Z4 because customers cars come first! Got good plans for it though!
I normally work in the evenings now. From about 5:30 onwards. Spend the day with my lovely Wife and our border collie Izzie!
Not always possible but customers prefer me to repair/service their car late on so they dont have to be without it during the day!
And not forgetting i am a retired maths teacher so dont have to work too hard! In fact some days I dont work at all!
Andy.
Thanks for your questions.
I strip down the calipers completely and degrease them in a bucket of shower gel and hot water! Works well and kind to the hands! And cheap. I then stick it in my vice and use an electric drill with these black nylon wheels stuck in the end. Works for hub flanges also. Amazing black abrasive wheels they are.
And i use a carbide burr on a die grinder to get into the nooks and crannies.
Loads of patience needed, and take your time.
Degrease again and panel wipe.
I use 2 different methods to paint them.
If I have plenty of time, I spary a 1K etch primer on like this
Then spray with a white primer from anywhere really! Normal aerosol.
Then spray a few light coats of red smoothrite
And leave to dry for a few days and then reassemble everything.
The other method is a lot quicker.
Derust as above and degrease, then spray with HYCOTE red caliper paint. Couple of coats.
Dries damn quick. Then reassemble.
The softtop was done with the stuff only. Following the instructions. Nothing special.
Hope this helps.
You are always welcome to call in anytime. Not sure when Ill be working on the Z4 because customers cars come first! Got good plans for it though!
I normally work in the evenings now. From about 5:30 onwards. Spend the day with my lovely Wife and our border collie Izzie!
Not always possible but customers prefer me to repair/service their car late on so they dont have to be without it during the day!
And not forgetting i am a retired maths teacher so dont have to work too hard! In fact some days I dont work at all!
Andy.
markplant said:Hi Andy we've got a breakfast meet on Sunday 24th July at the Eyre arms in Calver if your interest,
We are in London that weekend. So, unfortunately not gonna make it then.
Do you have any other meets? Would love to meet some of you.
Thanks for offer though. Much appreciated
Andy.
Turned my air con on today and got hit in the face by warm stale air!! Nice 
So off to Auriga cars in Coal Aston, Derbyshire where my mate is the workshop manager, and pumped back up to preesure.
This car is like a bloody teenager! Moody, and the more it gets, the more it wants!!
Andy.
So off to Auriga cars in Coal Aston, Derbyshire where my mate is the workshop manager, and pumped back up to preesure.
This car is like a bloody teenager! Moody, and the more it gets, the more it wants!!
Andy.
benneyboy1
Member
Hi Andy
Thanks for your response to my post as promised heres a few issues that I have identified for you to add to your to check list for your Z4.
1) Engine Fan - After being sat in a traffic jam for 45 minutes one day I noted that the engine temperature guage had redlined (whoops) and immediately switched my engine off to let it cool down. I ended up replacing the engine fan unit and the control module that is attached to it. This was done by my local garage but I am not convinced it was the right diagnosis. As I had already mentioned issue number 2 below to them which they said was linked.
2) Parasitic battery drain - If I leave my car standing for more than 2 days the battery drains down completely my local garage blamed it on the engine fan control unit which I had swapped out but the problem still continued. Its widely reported on the forum that the stereo head unit is a known cause. With everything switched off and left to settle for approx 20 mins I was draining 1 amp across the battery. Pulled the fuses for the stereo head unit and had an immediate drop to 0.5 amp so I have fitted an illuminated kill switch on the power feed to the stereo head unit. I have yet to locate the culprit for the remaining 0.5 amp drain when driving every day its not an issue so when its parked up I have to fit the trickle charger. Just havent had time to pull the other 50 or so fuses!!!!
3) Water under passenger seat - Giving the car a through clean I found a lake under the passenger seat worked out this was caused by a large section of the waterproof membrane coming away from the inside of the door so I had to take all the trim off and repair. Another common Z4 problem.
4) Stereo speakers - My car is only fitted with 6 speakers so only the the tweeters in the top of the door panel and blanking plates in the actual doors so if you like your tunes you may want to upgrade, you can take a feed from the tweeter if you dont have any speakers or feed in your actual door.
5) Roof motor - Fortunately mine works but known to fail due to water ingress caused by blocked drains lots of posts on the forum on this and preferred solution is to relocate into the boot.
That should keep you going for a while if I discover anything else I will let you know. Regards benneyboy1
Thanks for your response to my post as promised heres a few issues that I have identified for you to add to your to check list for your Z4.
1) Engine Fan - After being sat in a traffic jam for 45 minutes one day I noted that the engine temperature guage had redlined (whoops) and immediately switched my engine off to let it cool down. I ended up replacing the engine fan unit and the control module that is attached to it. This was done by my local garage but I am not convinced it was the right diagnosis. As I had already mentioned issue number 2 below to them which they said was linked.
2) Parasitic battery drain - If I leave my car standing for more than 2 days the battery drains down completely my local garage blamed it on the engine fan control unit which I had swapped out but the problem still continued. Its widely reported on the forum that the stereo head unit is a known cause. With everything switched off and left to settle for approx 20 mins I was draining 1 amp across the battery. Pulled the fuses for the stereo head unit and had an immediate drop to 0.5 amp so I have fitted an illuminated kill switch on the power feed to the stereo head unit. I have yet to locate the culprit for the remaining 0.5 amp drain when driving every day its not an issue so when its parked up I have to fit the trickle charger. Just havent had time to pull the other 50 or so fuses!!!!
3) Water under passenger seat - Giving the car a through clean I found a lake under the passenger seat worked out this was caused by a large section of the waterproof membrane coming away from the inside of the door so I had to take all the trim off and repair. Another common Z4 problem.
4) Stereo speakers - My car is only fitted with 6 speakers so only the the tweeters in the top of the door panel and blanking plates in the actual doors so if you like your tunes you may want to upgrade, you can take a feed from the tweeter if you dont have any speakers or feed in your actual door.
5) Roof motor - Fortunately mine works but known to fail due to water ingress caused by blocked drains lots of posts on the forum on this and preferred solution is to relocate into the boot.
That should keep you going for a while if I discover anything else I will let you know. Regards benneyboy1
Thanks benneyboy1!
Quick update for everybody.
The CAT code P0420 bank 1 sensor 2 code has now gone!! Fuel trims were good at all times but post CAT sensor was all over the place. To save everybody looking back at the story, I found a coil pack in the drivers door pocket when I bought it. So perhaps it failed and wasnt changed for a time and contaminated the CAT. Who knows.
Anyway after 2 doses of CATACLEAN the waveform is flat and perfect! No more CAT codes! Amazing stuff. Type CATACLEAN in google or youtube and read the reviews and the results from testing labs. Incredible.
Anyway, onto the lift we go today to solve this problem...
The drivers front undershield not fitted correctly. In fact it was cracked all over the place behind the wheel on the bit that goes under the floor.
I tried to photograph the damage here
Another crap photo out of focus. Sorry.
Plastic welded it back together. Here's an inprogress photo
Then spotted the panel that goes under the foglight was cracked. The bit that goes here (shown removed)
Welded.
Successfully put back.
continued..................
Quick update for everybody.
The CAT code P0420 bank 1 sensor 2 code has now gone!! Fuel trims were good at all times but post CAT sensor was all over the place. To save everybody looking back at the story, I found a coil pack in the drivers door pocket when I bought it. So perhaps it failed and wasnt changed for a time and contaminated the CAT. Who knows.
Anyway after 2 doses of CATACLEAN the waveform is flat and perfect! No more CAT codes! Amazing stuff. Type CATACLEAN in google or youtube and read the reviews and the results from testing labs. Incredible.
Anyway, onto the lift we go today to solve this problem...
The drivers front undershield not fitted correctly. In fact it was cracked all over the place behind the wheel on the bit that goes under the floor.
I tried to photograph the damage here
Another crap photo out of focus. Sorry.
Plastic welded it back together. Here's an inprogress photo
Then spotted the panel that goes under the foglight was cracked. The bit that goes here (shown removed)
Welded.
Successfully put back.
continued..................
Interestngly, when the underwing shield was removed it exposed a very dry ABS pump and big earth connector (ie no protective lube or coating at all.
Notice the 2 thick brown wires?
No protection either.
So all liberally sprayed with a synthetic extreme lubricant.
And look how dry the underwing is. Especially the brake pipe and connector here
Again, sprayed thoroughly.
Notice the 2 thick brown wires?
No protection either.
So all liberally sprayed with a synthetic extreme lubricant.
And look how dry the underwing is. Especially the brake pipe and connector here
Again, sprayed thoroughly.
Now, next interesting find.
Bear in mind that the car was MOT'd just before I picked it up in late january this year with a PASS.
Have a look at the state of the front to rear brake pipes
These were obviously then perfect 6 months ago!! What a joke
Guess what I'll be doing next as a matter of urgency.
Andy.
,
Bear in mind that the car was MOT'd just before I picked it up in late january this year with a PASS.
Have a look at the state of the front to rear brake pipes
These were obviously then perfect 6 months ago!! What a joke
Guess what I'll be doing next as a matter of urgency.
Andy.
,
Those brake lines are shocking!! Best check mine now 
How easy are they to change? DIY job for a novice, or require a degree of technical ability?
How easy are they to change? DIY job for a novice, or require a degree of technical ability?
