Thread: idler pulley broke, replaced it, now it doesnt act right

My idler pulley broke so i bought a new one and installed it, figuring it would be back to normal, it started up normal and then 15 secs later started idleing funny and there was a knocking. i drove it home, and a few mins from my house there is a big hill so i wanted to be easy on it but i had to get up the hill so i pushed it a little and it started acting normal. the next day i started it b4 i went to work and it was normal still and even when i left work. then the next day started it b4 i went to work it was normal till i left and few mins from my house it started acting up again, then went back to normal b4 i got to work, and when i left work i started it and it was messed up again, then a few mins from work it was fine again. weirrrrddd!!!

I have heard something about the coupler in the supercharger making a knocking noise, I was wondering if this could b the prob.

Are you able to estimate what part of the engine bay the sound comes from?
Are you able to get a video of this?
Most auto parts stores will scan your car's pcm for trouble codes. If you are able to get a code, this would be useful.

If you remove the belt from the supercharger, and you still hear the noise, then it is definitely not the supercharger. A bad coupler sounds like rocks in a tumbler.