Ground Loop Problem

[david712370]

So once again I think I have a ground loop problem. When I have the radio on but at volume 0, I can hear engine noise in my speakers. I have the power rem and ground from the head unit running on the passenger side and the signals running down the drivers side. I read that it is better to ground the head unit to the same place that the amp is being grounded so i ran a wire to do so. I decided to ground the main amp terminal to the bolt in the trunk that runs under the bar that runs across the car. I believe it the bolt here is suppose to be used for securing things down. It has a black plate attached to it that comes out from the carpeted mat (please forgive my descriptions). I am running 0/1 guage wire for the power. And I have upgraded the ground going to the batter to 0/1 guage wire as well. In the front dash I have the Peswiac ground, steering wheel ground, and head unit ground all going to one wire that goes to the amp ground that I described above. If anyone has any ideas how i might be getting this noise I would appreciate any feed back. The engine noise is not too significant, but it is there. I would say that I cannot hear it at volume level 3 on my kenwood ddx714.