I had mine replaced it was making noise as well.I was able to get a rebuild from a company in Mass,It is diffucult to change it but I did it without removing the manifold it is possible.I would check the springs and lines to it most likely you can clean the throttle body it must be sticking if you need a throttle body I can give you the address they back there stuff up for rebuild.It took about two hours to take out and two to put it back in withought removing the manifold it must be turned around it will come out so hope this helps.