Which bolt is this? - Bimmerfest - BMW Forums

Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > Z Series > E85 / E86 Z4 (2003-2008)

E85 / E86 Z4 (2003-2008)
E85 Z4 Roadster, E86 Z4 Coupe, E85 Z4 M Roadster, and E86 Z4 M Coupe talk with our BMW gurus here.

Thread Tools Display Modes
Old 02-24-2020, 12:49 AM
manoweb manoweb is offline
Registered User
Location: Hayward, California, USA
Join Date: Apr 2009
Posts: 66
Mein Auto: Z4
Which bolt is this?

I was changing oil the other day on my wife's Z4 and I noticed this bolt:

Click image for larger version

Name:	z4bolt.jpg
Views:	77
Size:	81.3 KB
ID:	882981

It's a 13mm head, I tried to tighten it but it was pretty hard to turn, so I started trying to lookup some information on what it is. I don't want to torque it down inside the aluminum block and strip something. Any advice?
Reply With Quote
Sponsored Links
Old 03-10-2020, 06:27 AM
impreza276 impreza276 is offline
Officially Welcomed to the 'Fest
Location: US
Join Date: Nov 2006
Posts: 538
Mein Auto: BMW Z4 3.0si 2007 AT
This is a guess but I vaguely recall seeing such a bolt used too assist in the adjustment of the alternator, and it was meant to stick out just like that. My advise is not to touch it for the moment, it probably is just fine.
Reply With Quote
Old 03-10-2020, 10:06 AM
Clearancediver's Avatar
Clearancediver Clearancediver is offline
Officially Welcomed to the 'Fest
Location: Victoria BC, Canada
Join Date: Oct 2012
Posts: 688
Mein Auto: 2004 Z4, 2009 Nomad mc
Likely used to adjust the alternator to “line” up into the proper position for its pulley to be parallel with everything else when v belt installed.

If you look closely at what it “pushes” against... you will see that if you loosen off the bolt securing the alternator in position, you would be able to adjust the alternator backwards if you tighten “that bolt”... alternatively... backing off on “that bolt” in question will allow the alternator to move slightly forward.

I’d just leave it alone as suggested as it would have been a factory adjustment at time of assembly.

Sent from my iPhone using Tapatalk
Reply With Quote

See More Related BMW Stories

Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > Z Series > E85 / E86 Z4 (2003-2008)
Today's Posts Search
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump

All times are GMT -7. The time now is 01:27 AM.

Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
© 2001- VerticalScope Inc. All rights reserved.