OK, maybe I'm just going bananas over this, but lately it seems to me that sometimes the noise is gone or much lower. This week engine light came on. I ran a scan and it showed code for secondary air injection pump. Now, a bit of history, I replaced the pump a few months ago because the motor brushes burned through the casing of the motor and obviously motor was not working anymore so I had the same code and engine light. This time I checked the relay module, and re-soldered relay pins which looked like cold soldered joints and cleaned the relay contacts which were somewhat burned. Cleared the codes, and now for two days no engine light so I think thats all set. Now what I did notice in the last few days is that my "rolling down the hill at idle" seems much easier. The car seems to free-roll at idle better now.