My Enthusiest 6MT with 3500 miles started making two weird noises around the same time 2 weeks ago.
The first noise is heard in 1st gear when you let off the gas and "coast" back down to a stop. On a real hot day I can actually hear it applying throttle in first and driving slow...Plus on a real hot day when the cars warm depressing the clutch in first it can be heard (but not as loudly as coasting in 1st gear which I can hear when the cars cold).Its a weird growl or Vrrr noise that sounds like a flywheel or somthing. Its embarrasing! Cruzing slow in second gear its silent. My 1st to 2nd shifts do sound a bit clunky though when shifting slow too..Dont know if theres a connection....

The other noise is a intermitent "thunk" from the rear area I only hear taking off. Occasionally when turning (say from a light) I hear it once im going about 5-10 MPh. Sounds like heavy cargo shifting in the trunk but nothings back there.My spare and tools are all secure too.

Anyone had any of these problems?

 

Search the forums, I seem to remember someone having a thunk from read passenger side. They got their shock mount replaced and it fixed it.

 

I think I get one of your sounds, going slowly in 1st and nuetral, doesnt seem to matter whether clutch is in or out, but only when Im off the gas, either engine braking or coasting, I get the sound as tho the gears are grinding or something...

it used to be reverse only, but now I got it in 1st too, and it used to be only with clutch out, but now its even when engaged...

 

I have a clunky shift to second when cold, and a slight noise when in neutral with the clutch out. Other than that though, the tranny is working quite well.

19,500 miles so far.

The only noise I had coming from the back was due to the large white nut on the spare tire being loose. It was rattling a bit though; it wasn't really a clunk.

When I leave a CD cover in the little pockets behind the seats and go fast around corners, I can hear it thunking around. Do you have anything in those cubbies?

-D'oh!