More expensive? The idler and tensioner pulleys would be ALOT cheaper than an ac compressor

I believe those pulleys are available in anodized aluminium with replaceable bearings because they have been known to fail with catastrophic damage to the fan, rad, hood etc. I believe they are fitted almost as a matter of course to the E31 V8 cars.

I think they are available from Tom at www.wuffer.net from the PhoenixMotorsport tab.

X5Girl, xxx

an update finally - - after several weeks and over $4k the mech opened up took apart the engine and the sound is gone ... i don't exactly what the problem is but it was mighty costly

4000 dollars later and the engine being taken apart i get the car back and it doesn't whine anymore. that'll teach it for being a spoiled little brat.

i really appreciate the feedback and my mech was impressed when i was talking about idle tensioner pulleys and stuff. thanks

That's exactly what i'm hearing...alternator & water pump were replaced by dealer, then suddenly this "noise" introduced itself :( Feels like she's lost some low-end torque. Couple questions:
-is this normal wear or could it be a result of the above mentioned install?
-certainly this repair cannot cost $4k, or can it? :confused:
-i have a 2 hour road trip this weekend, is it safe to continue driving?
-seems the part #'s are the same for the 4.6is
RealOEM.COM * BMW E53 X5 4.6is BELT DRIVE WATER PUMP/ALTERNATOR

I have engine noise and vibration after 2000rpm. I think its alternator.
I checkek my friends X5 and noise was same,but much less.
Can someone check if your engines have some noises on 2000-3000rpm.
My x5 2004 4.4i , also my friends 2004 4.4.
Maybe this symptom is for N62 engine only?

It is normal wear and tear on those brittle plastic tensioners and as they have been disturbed, the belt may now be tighter making the noise worse. If the tensioner/idler shatters then it will cost big bucks to fix if it damages the rad, water pump, hood and fan as it disintegrates. Trick alloy pulleys are available for the V8 with replaceable bearings and if you intend hanging on to the car, this is the way to go. See pic of M62 install.

X5Girl, xxx

Just the pic i needed to see...Cheers X5Girl!!! So member primetime says he drove for 5 months with that sound, i understand the damage it can cause if it shatters, so is this something that requires immediate repair or can it wait? I noticed this sound about two weeks ago.

A long delay could cost you dearly. I would do it as soon as you can but you would be pretty unlucky if it completely failed on you that quickly.

X5Girl, xxx.

Well...not gonna take any chances. Just booked appointment at indy for replacement. If i had more time, i would've ordered the aluminum pulleys from PhoenixMotorsport. Gonna have to go with the OEM plastics for now :( Too bad we don't get a warning light when pulleys are going bad :confused:

2 dealer diagnostics failed to identify this...thanks to X5World, i was able to locate the problem. I believe it's time to upgrade my membership here... :D ...