Now, it doesnt happen all the time... but if I say, start the car with the a/c on, right as i hear the a/c compressor click on, i also hear this muffled 'thump' that comes from the general area where the compressor is located (front rightish) (still in P by the way)... when i first heard it the other day, I thought the a/c was completely shot... but a few seconds later the air starts coming out cold... so it seems like it has something to do with the a/c (it doesnt make that thump when i start the car with a/c off), but it doesnt do it all the time with it on... any ideas?