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Old 08-22-2011, 11:30 AM
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bluebee bluebee is offline
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Location: San Jose, California
Join Date: Mar 2008
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Mein Auto: 02 BMW 525i M54 auto 130K
For the record, here is a nice picture of the adjustment arc of the V8 hydraulic tensioner today:
- E39 (1997 - 2003) > AC tensioner installation

NOTE: The I6 hydraulic tensioners do not have this adjustment arc.

Originally Posted by bimmerteck View Post
  • I6 E39 mechanical tensioners (no adjustment necessary nor possible)
  • I6 E39 hydraulic tensioners (no adjustment necessary nor possible)
  • V8 E39 mechanical tensioners (no adjustment necessary nor possible)
  • V8 E39 hydraulic tensioners (no adjustment necessary component removal facilitated via the bolted arc)

In addition, cn90 referenced a nice DIY:
- 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.

See also:
- 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)

Last edited by bluebee; 08-22-2011 at 10:59 PM.
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