Not joined yet? Register for free and enjoy features such as alerts, private messaging and viewing latest posts and topics.

Ignition/crank fail repair

Post Reply
StigJ
Member
Member
Posts: 586
Joined: Tue May 04, 2010 8:58 am
Location: Sola, Norway

Ignition/crank fail repair

Post by StigJ » Tue Jul 10, 2012 6:43 pm

I've had some problems now and then with my Z4 Coupe that it would not start. Did run a diagnostic last year but nothing came up. Just some communication errors that we did not find any answers to. I think also my Intravee is making some mess.
So I started investigating a little

In the video below you can see that when I move the key from step 1 (acc) to step 2 (ign) sometimes only the airbag light lights up in the ign position. When try to start the starter kicks in, but that is it. So there is no difference between acc and ign.
If I take the key out and try it again it usually works fine.
Here you can see what happens:
http://youtu.be/gcYG9Vn5mSM

So I asked my mechanic what it could be. Try to change the ignition switch he said. Its just the last part that the wires goes in to. Its not the complete lock.
Ok. so I first checked how much a new one would set me back. Almost 120$. Yeah right! So I bought two used ones for 15$ (for both). Bought two if one of them would fail.

Then time to do the change.

here you see the two switches.

Image
Image

Its no. 3:
http://realoem.com/bmw/showparts.do?mod ... g=32&fg=30

Off with the bottom part of the steering column. Its only one screw just beside the lever for adjusting the steering wheel. Then wiggle it a little to get the two pieces to part.

Image

Here you can see the ignition switch where the wires is connected.
Image

Just pry the little lock to disconnect it.
Image
Image
Image

The switch is held in place by two small flathead screws that is located under the red screw locking paint.
Image

Just loosen them a litle and pull out the switch. Put in the new one and fasten the screws and connect the plug. Now you can do a test if its working as it should.
It looks like I found the problem and got rid of it :)
http://youtu.be/Ml1zYHYNzl0

I put some screwlock glue back in the holes and reassembelede the steering column. Now its to hope that the problem stays away.
Image

As the nosy person that I am I had to open the old switch to see what was wrong. Looks like its wear and tear on the plastic.
The second step (ign) is the two brass parts on the right side of the 3 contacts.
Image
Image

A little video of how it works:
http://youtu.be/B-YQt2gFaQk
Image
Hellrot '06 BMW Z4 Coupe 3.0si
Instagram: @StigJ77 & @bmwe86driver

User avatar
AlanJ
Lifer
Lifer
Posts: 7725
Joined: Thu Jul 17, 2008 5:54 pm
Location: North Yorks

Re: Ignition/crank fail repair

Post by AlanJ » Tue Jul 10, 2012 7:01 pm

Good write up. Thanks :thumbsup:
///M tri colour steering wheel, mud flaps and loads of other extras! ZHP illuminated gear lever..... Pre Purchase Checks,Getting the Best out of Dealers http://www.bmwz4roadster.net

RichardP
Member
Member
Posts: 95
Joined: Thu Aug 25, 2011 7:06 am

Re: Ignition/crank fail repair

Post by RichardP » Wed Jul 11, 2012 5:29 pm

Ignition switches appear to be a week point in many BMWs.

Coul you expand a little on "I think also my Intravee is making some mess."

StigJ
Member
Member
Posts: 586
Joined: Tue May 04, 2010 8:58 am
Location: Sola, Norway

Re: Ignition/crank fail repair

Post by StigJ » Wed Jul 11, 2012 9:12 pm

Well, sometimes it does not respond at all, sometimes it cant "start" the iPod (maybe thats the iPods fault. Old Nano gen. 1) And sometimes the whole radio and screen freezes so only the steering wheel buttons works. :thumbsdown: I will take out the Intravee to try to update the software or something. I will do some digging when I get some free time.
Image
Hellrot '06 BMW Z4 Coupe 3.0si
Instagram: @StigJ77 & @bmwe86driver

User avatar
colb
Senior Member
Senior Member
Posts: 1617
Joined: Wed Nov 13, 2019 9:45 pm
Location: Newport, South Wales UK

Ignition/crank fail repair

Post by colb » Mon Jul 27, 2020 7:31 pm

Nice write up and pics of the switch, been into mine when diagnosing the starter problem, had it out and sprayed with electric cleaner, refitted and checked the ignition feed to the starter, its the black wire with blue trace, key to start position and get 12volts on it that signals the starter solonoid. Mine checked out switch end and starter end, pulled the starter and bench test revealed it was dead. Should get my replacement tomorrow to put it back together and test. I do have a used switch on its way as well just in case mine fails in the future.
Z Shed Cymru member
1999 1.8 Z3
2003 2.5 Z4
1998 Honda Deauville 650
If the forum helped you, why not help the forum back. Thats the Z4 way! :thumbsup:
https://www.paypal.com/cgi-bin/webscr?c ... source=url

Post Reply