Loud Noise when Coasting and Clutch is Disengaged (Peddle to the Floor)

[slick230]

Car: E46 M3 (2003)
Miles: 37K

While rolling up to a stop light yesterday I noticed a loud noise from under the car which sounded like a bunch of marbles in a car bouncing around. I just finished shifting from 4th to 3rd and then into second and when I disengaged the clutch and rolled to a stop the noise started. I figured I picked up a rock or something and it was in the rim. The sound went away and I didn’t think much of it. I then heard it again the same day under the same conditions and then again when I was parking my car at work today.

I am starting to think there is a problem either with the clutch or transmission.

I just had the transmission fluid flushed on 06/06/11 by a very reputable shop.

Any ideas?

Thanks!

[Bob]

I need a little more diagnostic info., is this only when moving, I would suspect a throwout brg., but that would occur while motionless,if only when moving, its not a throwout brg., the trans. flush was refilled, I hope.

[slick230]

Bob,

Thanks for the reply.

When it happens it is only while moving slowly, after I shift down through the gears using the transmission to slow the car. The car is usually in second, sometimes in first (if I am pulling into a parking space) and I have the clutch peddle to the floor to roll to a complete stop. Once stopped the noise goes away.

I never hear it while accelerating, shifting (first to sixth) or shifting between gears at speed.

I hope it was refilled as well...

I need a little more diagnostic info., is this only when moving, I would suspect a throwout brg., but that would occur while motionless,if only when moving, its not a throwout brg., the trans. flush was refilled, I hope.

[Bob]

Did you change brands/weight of tranny. fluid, might be audibly louder in the lower gears while coasting, if you changed to a thinner/synthetic, its ATF, right? ?

[slick230]

I am not sure what was changed since it was done while I was overseas. I trust, maybe I shouldn't, the shop knows what they are doing. But last night the noise happened again while down shifting and entering into a traffic circle and I was able to feel something hitting the shifter while the rattling was taking place.

Did you change brands/weight of tranny. fluid, might be audibly louder in the lower gears while coasting, if you changed to a thinner/synthetic, its ATF, right? ?

[Bob]

Now we're getting somewhere!, "something hitting the shifter" is a classic symptom of a shredding guibo, an easily changed driveshaft part, or maybe broken tranny mts, an even easier fix..