When my ari conditioner truns itself on, it makes a lot of noise, big bang and rattaling, It is central air. How do I stop it form making so much noise when it truns itself on.

Unless you can tighten the windings inside the compressor, be GENTLE and shim something underneath the condensor itself.

XenoSapien

First you must determine where the noise is coming from, open the panels and listen during startup, it may be a out of balance blower wheel .

First you must determine where the noise is coming from, open the panels and listen during startup, it may be a out of balance blower wheel .
.... the balancing clip may dropped off or loose