I have an 07 Cobalt LS. changed the factory stereo years ago when car was almost new, not had an issue at all- until recently.
I have an alpine w505 dvd unith with the h100 imprint module and a pheonix gold sd1300.5 amp, and am all of a sudden getting engine noise in the stereo. I have checked and remade all ground in the dash as well as in the back at the amp and battery. Even replaced the battery with a new AGM from advanced Auto. Got so frustrated that I changed the deck out for a JVC cd player that is almost new and known to be in good condition.
Can anyone give me some direction. I am guessing a ground under the hood, or maybe even the silica shields on the coils at the plugs.
any ideas fully appreciated

 

you could look into a noise filter that is what they are made for

 

tried that as well and no hope. the one I tried was rca based

 

do you still have the H100 connected?

 

it is still connected, but have pulled everything out of the chain and hooked rca's directly to the head unit and still there. I dont think the noise is in the stereo equipment. everything other than speakers has been changed with no change in sound

 

if you plug an external MP3 player into the amp is there still noise? if so then its the amp if not try at the HU side of things. if theres noise there then its the RCAs or HU

 

thanks JJ

 

did that work? did u get it figured out?