Symptoms of a failing AC Compressor
Warm air conditioning
In theory, climate controls are simple. You ask for cold air, you get cold air. You ask for hot air, you get hot air.
Things get complicated when you ask for cold air and get hot air. But that’s exactly what might happen if your AC compressor is busted. No, you're not going crazy.
When the AC compressor’s life is over, your air conditioning system won’t have a way of cooling down the air that it’s sending into your cabin. Then you’ll get warm air, which isn’t so great on a sunny summer day.
Rattling noise
Your car should generally make two noises: The sound of the engine, and whatever you're blasting through the stereo. That's about it.
If it makes more noises, you might have some issues on your hands. If the AC compressor is broken, you may hear a rattling noise, due to the compressor being loose, and...well...rattling around. Makes sense yeah?
So, when you hear a noise, get it looked at. And when that noise is rattling, it may be the compressor.