When AC is on ,my 2009 ford focus my car struggles when giving gas and sound like chattering coming from the engine area
it has 58,000 miles and is ok when AC is not on. also when going up an incline and having AC on makes the chattering louder its not the AC but the engine area, sounds like someones playing a tamberine.
Can you provide more details? Like what you mean by chattering? Does it doe it when idling? Accelerating? Etc?