Depends on the noise. If it's a high screaching type of sounds the a/c belt is probably worn or dryed out so replace it. If it's a rattling sound it's probably a bearing that has gone bad.
A bad compressor belt can cause a whistling noise while running the air conditioner. A bad engine can also cause this noise.
There are a few things that might cause an air conditioner to make a rattling noise. It could be that the there is dirt and debris in the cabinet. If this is the case, cleaning the cabinet should stop the rattling. The reason could also be loose panels on the cabinets. The fan could also be bent and no longer straight.
have it checked you could have bent the axle and the noise would be the bearing
back struts are bad or exhaust is loose
could be a bad bearing on the air conditioner clutch assembly.
Could well be worn bushes in the suspension arm ( It was in my old civic )
cv joints
if it makes a loud whinning noise when you turn power steering pump bad or needs fluid if not it might be a popped belt
It could be objects shaking in the trunk or something loose on the rear license plate or a problem with the catalytic converter or exhaust pipes.
A bad starter might make a noise. The starter could also go bad with no noise or warning. However if the starter is making noise then there is a problem that could cause failure at any time
Could be one of a number of things, as it could be in any vehicle.
wheel bearings, worn brake pads, dry u-joints could be one of many sound travels on a vehicle but start with those