I have 2000 Civic Si and have just got done rebuilding the tranny, (bad input shaft bearing) new clutch, plugs, all new belts and motor mounts.. All went smooth except now why temp gauge will fluctuate like never before... i seems like it may be running hotter than normal when i am sitting in traffic and lower than normal and low temps at night...

It also has begun to make a almost humming sound when ideling after running for awhile???? any ideas?? it changes pitches and almost sounds like music..lol not really though

Does the temp gauge sound maybe like my theromostat?? or maybe a radiator???

As far as the humming sound i am not sure but it doesnt sound good....


Would appreciate any help.. thanks

 

try checking the temp gauge sensor as far as the fluctuation goes... and i'm sold on the humming sound.. it might be the gauge. but idk what to tell you for that one.. good luck