Engine groaning bearing sound

[E34orientblau]

Hi guys, I just acquired a 1994 530i Touring, its in great shape. But a couple of days ago I was driving it and noticed a groaning bearing sound, like a bad a/c pulley or something, at all speeds. On the way home I smelled burning rubber really strong and made it home safely. I havent driven it since, I took both belts off and all pulleys spin free, and make zero noise. So I put the belts back on and started it. I can feel the vibration of the noise with my hand on the oil filter housing. I can also feel it in the large hard plastic duct that runs right next to the power steering pump. Its a large diameter hard plastic duct, it looks like an air cleaner duct pipe, it runs right up into what looks like the frame or something. Anyways, could this groaning be my oil pump making noise? Im afraid to drive it as it sits. Thanks

[Jack Dabsy]

Hiya
It's really hard to diagnose from where I am matey !!
What is the engine temp like? Does this noise occur with th A/C on AND off?
If the oil-pump was making this noise then I would guess that it may be failing, oil-pressure would drop substantially !!

[E34orientblau]

The temp is fine. No problems there. The noise I am hearing happens at all times, at idle and on up through the rpm range.
Ive noticed that alot of folks on here are located within european countries. Me being in the USA, is that unusual on this forum?
Thanks.

[E34orientblau]

I will pull it in to my shop this weekend and begin the process of elimination. I was just wondering if anyone had an idea that would shorten my searching time in finding the culprit. Either way I will find it this weekend.

[brettski]

Does the pitch of the noise vary with the revs?

[E34orientblau]

Yes, at driving speeds, the pitch gets higher. At idle its a low grumble. I dont hear it at all at rpms higher than about 3000, but its audible from idle, on up to about 2500-3000. And as you were asking, it does change pitch with revs.
Thanks

[Jack Dabsy]

I am clutching at straws here, a dodgy viscous-fan would be an easy place to start...

[brettski]

Maybe an alternator, power steering or water pump bearing?

Get hold of a mechanics stethoscope (or an ordinary long handled screwdriver) and try to pin the noise down to a specific component.

If you are using a screw driver, put the pointy end on what you are listening to, and the handle in your ear.

[E34orientblau]

I will try my stethoscope this weekend. Actually, I drove it today and the noise is gone. But, i did smell burning rubber twice, it would smell strong, and just as quickly vanish. Weird stuff guys.