Strange tranny noise on acceleration: help!!

[mitch_speed]

I have a 318is 1991 with a 2.5l M50 vanos swap with a 260 Getrag tranny.

The car was winterized until last friday.

There is a knock knock noise between 2000 and 3000 rpm (increasing in frequency when i accelerate)on 1-2-3 and 4. the sound dissapear when i pass 3750 rpm or when decelerate. the location of the noise is near the transmission mount.

Any ideas?

should i start looking for a another tranny?

thanks,

mitch.

[jlevie]

Check the guibo, center support bearing, and transmission mounts.

[Hallen]

And check the exhaust mounts too. The exhaust can thump against the things if not in the right place, especially near that mount that goes to the transmission. (Assuming the 318 is similar to the 325...)

[vic_325]

my tranny has the same sound, but it does it just while idling in neutral aswell as during acceleration in 1st 2nd and 3rd gears...

[kamotors]

And check the exhaust mounts too. The exhaust can thump against the things if not in the right place, especially near that mount that goes to the transmission. (Assuming the 318 is similar to the 325...)

+1 get the exhaust realigned, my exhaust was hitting against my rear bumper, and i had no clue what it was, because it would change with rpms and speed, also sometimes it wouldn't do it.