[buytamil]

06 - 325xi

I hear humming noise during acceleration only and it goes way when I take the foot of the gas pedal. If i press the gas pedal, the noise comes back.

The idler and tensioner pulleys are good.

what could be the issue ?

[ronjonsoflo]

Hey I've had this same "issue" with my car as well. I don't think it's something that needs to be repaired but maybe it can be remedied as I've always been bugged by this same issue.

[labrador]

Is it coming from the rear differential? Has the fluid been changed and how is the level and condition? Driveshaft and rubber pad?

Not familiar with the XI setup, whether it has a transfer case or not.

[buytamil]

Changed the front & rear differential fluid and transfer case fluid yesterday. Noise has reduced considerably. Drove for an hour and it was smooth.

All three fluids were dark and the rear diff fluid was stinky......

Rear Diff - BMW fluid - 1 Qt
Transfer Case - BMW fluid - .6 Qt
Front Diff - Royal Purple - 1 Qt

[e90yyc]

Make sure to reset your transfer case adaptations.

Some may say it’s not necessary, but I’m of the opinion that it’s 5 minutes well spent, assuming you have cable or tool.

[buytamil]

Originally Posted by e90yyc

Make sure to reset your transfer case adaptations.

Some may say it’s not necessary, but I’m of the opinion that it’s 5 minutes well spent, assuming you have cable or tool.

Is it a DIY or need to take it to stealer

[e90yyc]

Originally Posted by buytamil

Is it a DIY or need to take it to stealer

DIY as long as you have INPA or similar, or a Foxwell/Schwaben scan tool.

Got one of these?

[buytamil]

can you point to the DIY for the reset ?

[buytamil]

All,

Finally found the reason for the noise during acceleration. It is the power steering pulley. After tightening one of the 3 bolts, the sound went away and I am not hearing any scraping noise. Anyone know the torque setting for those 3 bolts ?

Thanks