Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

Please follow the links below to help get you started!

Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 5 Series > E39 (1997 - 2003)

E39 (1997 - 2003)
The BMW 5-Series (E39 chassis) was introduced in the United States as a 1997 model year car and lasted until the 2004 when the E60 chassis was released. The United States saw several variations including the 525i, 528i, 530i and 540i. -- View the E39 Wiki

Reply
 
Thread Tools Display Modes
  #1  
Old 08-22-2011, 07:25 AM
mad12.1964 mad12.1964 is offline
Registered User
Location: Raleigh, NC
 
Join Date: Aug 2011
Posts: 8
Mein Auto: 540i
AC tensioner installation

Hello…. I need some help. This weekend, I wanted to replace the hydraulic tensioner on my 540i V8 and decided to remove the assembly (tensioner and bracket ) off the engine. Now that I replaced the tensioner I do not know how to align the tensioner with the engine body. I should have marked how the tensioner aligned with the body before I removed bolt ( see red circle) close to the roller (between AC and Crack shaft). I do see a line mark on the engine (not sure if that is to align the tensioner assembly or it is there for other reason) but do not see any marks on the tensioner assembly. So my question, what is the correct procedure to put it back together?
Attached Thumbnails
Click image for larger version

Name:	AC tensioner image.jpg
Views:	125
Size:	44.4 KB
ID:	289994  
Reply With Quote
Advertisement
  #2  
Old 08-22-2011, 10:06 AM
cn90 cn90 is offline
Officially Welcomed to the 'Fest
Location: Omaha NE
 
Join Date: Mar 2006
Posts: 12,913
Mein Auto: 1998 528i 5-sp 140K+
This is a nice DIY by "BlackBMWs" on Zionsville Cooling Overhaul.

It should help you, see Picture #4 or so:
http://forums.bimmerforums.com/forum....php?t=1139685
Reply With Quote
  #3  
Old 08-22-2011, 10:42 AM
mad12.1964 mad12.1964 is offline
Registered User
Location: Raleigh, NC
 
Join Date: Aug 2011
Posts: 8
Mein Auto: 540i
Thank you... I will check it out.
Reply With Quote
  #4  
Old 08-22-2011, 10:52 AM
cn90 cn90 is offline
Officially Welcomed to the 'Fest
Location: Omaha NE
 
Join Date: Mar 2006
Posts: 12,913
Mein Auto: 1998 528i 5-sp 140K+
The first picture you posted above seems correct, at that setup, the hydraulic tensioner pushes up the most.

More info:
http://autorepair.about.com/library/faqs/bl453d.htm
Reply With Quote
  #5  
Old 08-22-2011, 11:17 AM
bluebee's Avatar
bluebee bluebee is offline
Seek to understand,^Value
Location: San Jose, California
 
Join Date: Mar 2008
Posts: 21,499
Mein Auto: 02 BMW 525i M54 auto 130K
Nice tensioner adjustment arc picture!

I had not known about the hydraulic tensioner adjustment arc, nor about the nice DIY cn90 referenced ... so ... since we don't want to lose this information ... I'll take the liberty of cross referencing this information in the canonical pictorial tensioner threads ...
- How to tell if you have mechanical or hydraulic belt tensioners (1) how to switch from mechanical to hydraulic (1) and what is the difference between the two types (1) (2)
Quote:
Quote:
*******>********>
BMW 740il Serpentine Belt
Q. How do I go about changing the Serpentine Belt and, if necessary, the A/C belt on my 2000 BMW 740iL?


A. First thing you have to do is take off the fan and fan coupling.

Layout of Serpentine Belt
Then loosen nuts (1) and (2), loosen and remove the Serpentine Belt.

Use hex head (1) to preload adjusting plate to end of long bore (2) and tighten nuts (3). Installation:
Fit Serpentine Belt and check it is correctly located on pulleys.

The A/C belt is as easy as it looks. Just loosen the tensioner and replace the belt.

Attached Thumbnails
Click image for larger version

Name:	AC tensioner image.jpg
Views:	63
Size:	34.9 KB
ID:	290012   Click image for larger version

Name:	AC tensioner adjustment.jpg
Views:	13469
Size:	66.2 KB
ID:	290014  

Last edited by bluebee; 08-22-2011 at 11:24 AM.
Reply With Quote
  #6  
Old 08-14-2012, 11:39 PM
bluebee's Avatar
bluebee bluebee is offline
Seek to understand,^Value
Location: San Jose, California
 
Join Date: Mar 2008
Posts: 21,499
Mein Auto: 02 BMW 525i M54 auto 130K
For the record, this same question came up for the same engine in the E38 forum today:
> 7 Series - E38 (1995 - 2001) > Need Help with Serpentine Belt Tension?

Quote:
Originally Posted by wes1971 View Post
I am new to this site and just purchased a 1995 740 IL. The serpentine belt was loose and trying to tighten it but it doesn't stay tightened. Any help would be appreciated. I have never worked on a configuration like this one. Thanks
__________________
Please read the suggested threads, where the best always add value to those threads, either by pictures or by descriptions, so the next person with the same problem stands on your shoulders.
See also: E39 Bestlinks & How to easily find what you need
Reply With Quote
  #7  
Old 11-21-2013, 08:14 PM
bluebee's Avatar
bluebee bluebee is offline
Seek to understand,^Value
Location: San Jose, California
 
Join Date: Mar 2008
Posts: 21,499
Mein Auto: 02 BMW 525i M54 auto 130K
For the record, this question was asked again today:
Quote:
Originally Posted by supark View Post
I'm replacing the idler and deflection pulleys on my E39 540i, but when I checked it initially I couldn't figure out the correct way to tension the belt tensioner on the main serpentine belt. On the I-6s, you just insert a hex key into the idler pulley to get the serpentine belt in there - but there doesn't seem to be a place on the 540i tensioner. The bentley says to "turn a hex counter-clockwise".
Quote:
Originally Posted by rtw_travel View Post
I can't remember exactly without looking at it - but I do remember you need a wrench and a socket. There are two bolts on the same axis - if you turn them in opposite directions, you add tension to the belt.
Quote:
Originally Posted by KeithS View Post
It has automatic tensioners too. They look like little cylinders that push the idler pulleys. You loosen a nut then turn a cam about 10 degrees to unload the tension. The cam has a hex head on/in it (not an allen like the 6 cyl). At that's the case on my 2000.

Using at this convinient post as an example: http://www.bimmerfest.com/forums/sho...d.php?t=126965

Look at the idler pully just to the right of the AC compressor, Follow it down you will see the tensioner cylinder. Look near the bottom of the cylinder (near the oil pan) and you can see the cam I am talking about. The other one is pointing up between the waterpump and the alternator.
Quote:
Originally Posted by supark View Post
How do you apply tension to the little arm that's connected to the alternator/water pump belt though? I do see a hex to turn on the AC belt, but not on the alternator/water pump belt.
Quote:
Originally Posted by supark View Post
figured it out - I think. The hex you that you are referring to is the bolt holding the top of the tensioner on correct? Unfortunately if you apply too much press you end up loosening the bolt, but just the right amount will tension the tensioner correctly...
Quote:
Originally Posted by KeithS View Post
Only did this once but as I recall the bolt/nut you need to turn to add/remove the tension is welded to the plate/cam that you need to turn. This of course is after you have loosened the holdown screw/bolt. Once you loosen the the holdown screw the tension should release by itself, but you will need to turn the cam more to move the idler pully enough to get the belt off. When tightening need to hold the tension with one wrench while tightening the holddown with another.
Quote:
Originally Posted by supark View Post
Thanks, yeah - the bolt isn't actually welded on, but if you pivot it just the right way it'll let you tight down the tensioner arm without loosening the bolt.
Quote:
Originally Posted by cn90 View Post
I wrote this for both I6 and V8:
http://www.bimmerfest.com/forums/sho...d.php?t=213002

The principle is the same.

The rollers have 8-mm Hex (aka Allen) head. A 5/16" Hex socket is also fine.

To release the belt, scrape the inside of the bolt (dirt is inside) with a small nail or paper clip, then:

CW to tighten the bolt and to apply more pressure on the tensioner, thus releasing the belt.

CCW to remove the bolt and replace the roller.
Quote:
Originally Posted by rph74 View Post
You need 2 wrenches. One wrench to tension the serpentine belt, using, if I remember it right, a 17mm socket on the "fake bolt", while simultaneously tightening the lock bolt with the other wrench.
Quote:
Originally Posted by Flounderasu View Post
You tighten it as far as it will go.
Quote:
Originally Posted by Calicoastin View Post

How do you know how much tension is enough? Do you turn until the belt has no more "flex"?

I have a 540i with the "shock" type tensioner.

Thnx.
Quote:
Originally Posted by bluebee View Post
If you type /tensioner F3 into the bestlinks, this comes up, which explains, in detail, with pictures, the answer to the OP's question:
- How to tell if you have mechanical or hydraulic belt tensioners (1) & how to switch from mechanical to hydraulic (1) and what is the difference between the two types (1) (2) & how to rebuild your hydraulic tensioners (1) & how to re-grease your pulleys and rollers (1) & the answer to the question of adjusting the 540i hydraulic tensioners' belt tension (1) (2)
__________________
Please read the suggested threads, where the best always add value to those threads, either by pictures or by descriptions, so the next person with the same problem stands on your shoulders.
See also: E39 Bestlinks & How to easily find what you need
Reply With Quote
Reply

Bookmarks


Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 5 Series > E39 (1997 - 2003)
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 07:27 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
© 2001-2011 performanceIX, Inc. All Rights Reserved .: guidelines .:. privacy .:. terms