and this "knock" you are talking about Joe P.....would it be a constant one, or intermittent.
I can only hear it as I come to stop.....it rattles ...then when I stop it goes away.
I have left the car idling for 20 minutes....with the A/C on and could not get it to rattle. Only in the above mentioned senario.
by the way my A/C is woring perfectly....actually everyone compliments how cold it gets when they ride with me .
I don't know anymore!!