speaker static and distortion!!! please help

Well here is my problem, could someone please help me out!!! I have an alpine amp with 6 1/2, 5 ¼, and 6 X 9 Polk audio speakers. The 6 ½ and 5 ¼ are hooked up to the head unit and the 6 X 9 are wired into an alpine amp. I also have two 10 in kicker subs also wired into a separate amp. The problem is that I am having static and engine noise through my rear deck speakers. I installed a ground loop to the RCA’s and it took the engine noise out but am still having static and distortion. I have two amps that are wired up to my car separately with 8 gauge wire. This was the recommended wire gauge for these amps. These amp wires are run the same with the powers on one side of the car and the RCA’s on the other side. One amp is hooked up to my subs and is working fine. The second Amp is giving me static and distortion through the rear deck speakers.

This is what I have tried to do:
-changed to more expensive RCA’s- same problem
-moved the rca’s – same problem
-regrounded amp – same problem
-switched the power and grounds from the working amp to the static amp – same problem
-I installed a RCA loop – took the engine noise away completely, but still got the static, distortion
-checked the fuses – they are fine
-rewired the deck speakers – still got the static, distortion

Any tips or suggestions!!! This amp is in 100% working condition and was just taken out of a car. I am traveling in a few days and really need to solve this problem ASAP

sounds like you have tried everything possible with the amp. What have you tested with the speakers? Have you tried to play the speakers through another source? Off of the head unit or the other amp? Does your amp have a built in xover? If so check that...I have seen amps do funny things if a xover switch was not in the proper position or half way between two positions.