I recently had freon added at Servitek (450pesos) after that malamig na yung aircon pero after a few minutes of the aircon being on I hear a 'tok' sound from the engine bay. Pag naka off yung aircon nawawala yung sound. Also pag naka on yung a/c at cruising sa highway parang nde constant yung hatak.

Any ideas what can be causing the 'tok' sound? I'm going to replace the engine supports in a couple of months, may sira na yung isa, pero I dont think thats the one causing the sound. Any ideas? A/C cleaning lang kaya yung kelangan? Masyado madami kaya yung freon na nalagay?