When do I change the timing belt on my 2006 chysler sybring

If you have the 2.4L 4 cylinder engine, the timing belt is replaced under "severe duty service" at 90,000 miles, or in "normal duty service" at 120,000 miles. I would suggest every 7 years at the latest also, as rubber does dry rot and fail due to age. Your noise, however, may not be timing belt related. It could still be a pulley where your drive belt rides, or it could be a timing belt pulley or tensioner as well. This will take some good troubleshooting before you go to replace components unnecessarily perhaps. The 2.7L V6 has a timing chain, so I assume you are speaking of the 2.4L 4 cylinder motor.