changing idler pulleys

[cjenkins]

I am going to change the 2 lower idler pulleys on a 2000 5281. Can anyone tell me if they are the offset or center-set pulleys? Any tricks that would make the job easier?

[Jeron]

The engine has 2 belts: main and A/C

Each belt has an hyd idler arm with centered pulley. The main also has an offset deflector pulley.

The pulleys all have center caps you have to pop off with a flathead. They are held on with hex cap bolts so you need a hex socket set, socket wrench and a breaker bar or slip over cheater to make it easy.

On an E36 and E46 you can do the job by just removing the air box for the top belt and the under tray for the bottom.

[cjenkins]

Jeron,

Thanks for the info. The mechanic that worked on the car before said that I needed to have the 2 lower pulleys changed. He did change the main pulley on top. Would you have any idea what those part numbers would be?

Thanks
Chris

[Jeron]

It appears your A/C belt has a mechanical tensioner so the pulley is a different part number from the the main.

This is what I found:
Main Idler pulley 11281748131
Main deflector pulley 11281748130

A/C pulley 11281748130

[cjenkins]

In your last message, the A/C pulley and the main deflector pulley are the same number. The part that was replaced appears to be the main deflector pulley. Does that one sit off the alternator? Or does the same off-set pulley go somewhere else as well?

[cjenkins]

Also, is the Bentley BMW E-39 service manual the best manual to get? Any ideas on the best place to get that?

[Jeron]

I expected the A/C tensioner pulley to be the same as the Main but according to realoem your A/C tensioner is mechanical not hydraulic. It showed the mechanical A/C pulley to be the same as the offset deflector pulley 11281748130.

I suggest taking a look at what you have just to make certain. Compare that to realoem.com and also the Pelican parts search tool.