Weird Sound In Movement

[PanamaE30]

Thought I'd bring this up here to see if anyone has any ideas.

My car has a weird sound; kinda like metal scraping again metal. At first I thought maybe it was a worn brake pad or a twisted rotor or something. Nothing there. Then I considered it could be an exhaust issue, as the problem only happens in movement and I had a hole in the exhaust patched up recently. Nothing there either. Finally, I noticed that the issue only occurs when I'm in gear. If I rev the engine while in neutral, nothing. If I put the car in gear and gas it, i'll get the noise and it'll rise in pitch and volume the more i accelerate. Any ideas?

[Jand3rson]

My wife's 89 325i has a similar noise, kind of a rythmic metal-to-metal sound coming from the rear (sounds like anyway), that starts at around 25 mph, and increases with speed. I'm hoping it's just warped rotors, I don't know when they were last changed, but I'm leaning toward that being the problem.

[ryan_george]

Sounds like it might be something to do with the driveshaft support bearing or the diff.

[PanamaE30]

Hmm, well I'm sure it's not a rotor in my case..

I'll check the driveshaft support bearing.. the car sometimes feels like it's not rolling smoothly, could that be related?