Crunch/Grind sound at Startup
 

Hello, this is a weird one. It happens if the AC is already on before the car starts. So, if I leave the AC on, turn the car off, then strart the engine..I hear a crunch/groan/grind noise from the front-left of the engine bay. It's a 93 500SEL. Seems related to the AC compressor.

Besides just turning the AC off before turning the car off, is there something I should be worrying about. Some of the other drivers never care to turn the AC off at all, it is hot afterall.

Thanks for the help