I have a 1990 civic lx sedan 5 spd. when im in 1st and my rpms get above around 2700rpm it makes a strange noise. sounds kinda like a vibration. the noise continues as i go to higher rpms. it doesnt make the noise in any other gear including neutral and reverse. it doesnt seem to drive any different while making the noise either and the tranny shifts very smooth in all gears.

whats causing that noise? anyone know?

 

it might be the tranny i mean if it does it in first gear only than theres no other way of looking at it but the tranny.. first gear probalbly has wasted synchros inside... i had a b16 once and it only did noice in 3rd gear like this shshsshsh noice more i steped on it more it did it.. it was the tranny bro..