E34 540i/6 Strange Noise

[mheisig]

First time I've posted to this board, though I've lurked around for a few months. I was hoping to take advantage of everyone's knowledge and experience and make my life easier.

I have a '95 540i/6, 117,000 miles. I bought it back in September of '03, and unfortunately had to replace the clutch about a month later. While I was in there, I replaced the flywheel, exhaust hardware, seals, driveshaft center bearing, flexdisc, etc.

Over the past 2-3 days I've had a noise coming from the rear of the car, from what seems to be the center. The best way I can describe it is a regular, consistant "flipping" noise - kind of like sticking a card in the spokes of an old bicycle when you were a kid. Definitely sounds as if something that is rotating is hitting or rubbing at the same point every rotation. I won't have a chance to get the car in the garage to look at it until this weekend, but here's what I've noticed thus far:

-The sound is only noticable at low speeds, and the slower the speed the more noticable. The frequency of the "flip" decreases with speed.
-It happens in any gear, including neutral.
-Occurs under breaking as well as coasting.
-The sound completely disappears when throttle is applied, even the slightest bit.
-Doesn't appear to occur in reverse.

Not a whole lot of information I know. I was suspecting a warped brake rotor perhaps, but the sound is the same when breaking and not.

If anyone has any ideas or clues I'd really appreciate it.

Thanks in advance,

-Matt

[DueyT]

Hmmmm...could be the CV joints of the final drive (either of the two rear half-shafts connecting the differential output to the rear wheels.) This could be the equivalent of a FWD car with the ticking sound when worn CV joints are combined with large steering inputs...

Just an idea...mein2¢

Cheers,
Duey

[David Chen]

Or depending on the type of wheels, it could be a loose center cap or wheel cover.

[Reidal]

Could also be a fault in one of the rear tyres causing the tread to bulge.