So I've been setting this aside for a a while because I thoughtit was no big deal. When I'm using the AC I can feel the engine vibrate but only whe stationary. Let me mention that all four engine mounts are brand new OEM. Anyway, today I was refreshing the ac system and while I was at it I placed a cup of water on top of the engine with the ac on and with it off. The ripples with the ac on are drastically more violent. I don't feel it much when I'm inside but I don't think this is normal. Is this familiar to someone's car?