so my car doesn't run hot or anything but at lights it makes a gawdawful noise like something is grinding, but only after the tstat has opened up and everything is flowing. if i give it a little gas it goes away a little or sometimes i can just tap the gas real quick to get it to go away, at least till the next stop light or until i hit about 600rpm. any help would be appreciated, thanks

 

the bearing in the waterpump is probably going bad.