Audio Systems: Whizzing sound coming out of speakers after installing an amp, capacitor in parallel, rca line

Question
In my 2002 Civic I just installed a budget system. I used an MTX 4405(5 Channel) amp to run all 4 of my speakers and a 10" MTX sub. There also is a 1.5 Farad capacitor in parallel with the amp. Once installed all the channel works but i hear a whizzing sound out of all 4 of my speakers. I only hear the sound when the engine is on. Sounds like engine feedback noise to me, but I don't know how to get rid of it. I tried taking every precaution I can to prevent this. I run the power cable on one side of the car and the speaker cables on the other. And I made sure that the power cable is away from most of the engine components. Please help me figure this out. Thanks in advance.

Answer
Hi!
Is your headunit a pioneer? if so maybe the rca ouput is damaged if not you'll need a ground isolator, it's a small box to pass the signal trough so the noise induced on the wire is isolated try it on the radio end and on the amp end of the RCA line for best results.