Its making a grinding sound and dont wanna leave to losse

 

If you have truly isolated the sound to the idler pulley, then it can be serviced. Simple take it off, and with a small pick remove the bearing seals and inspect for damage. You can force new grease in easily with your thumb until it is full of new grease. Then carefully reinstall the seals.

I went through all this trouble, only to find that I had isolated the sound to the wrong pulley. It was actually my power steering pump making the noise. So I had to follow up by doing that job.

 

The best way to make sure you are working on the correct part is to use a mechanic's stethoscope.

 

pure water from a pump spray bottle on the suspect pulley will shut it up for a few seconds, long enough to find the culprit

 

If it's to the point of a grinding noise, then replace the bearing. You can buy the whole pulley for under $20 at the local autoparts store.