I just don't understand what an amp got to
do with the engine.
I don't see how it could cause your car's engine
to produce strange noises.

I you are refering to alternator whine then the
amp is most likely not the culprit but I would
suspect the wiring.

RCAs running to close to high power accessories could
induce this noise.
Same goes for the power and ground wires.
Also if the RCAs are to close to the power wire then
alternator whine is possible.
What you need is someone who knows what he's doing
and nows how to trouble shoot.
You didn't need a new amp you just need a new shop.

Louis.

__________________
Not always the smartest but certainly not dumb?