The bearing was squealing on the air pump of my 103 Motor and I removed it and put on a shorter belt. The car has been fine without it.
The pump is veary east to remove and replace if that is what you want to do. I removed mine in about 15 minutes. The most time consuming part is replacing the serpantine belt on a 103 engine.
The air pumponly functions for a short time when the engine is cold anyway.
To examine what is making the noise get a metal bar like a long 1/2 inch drive extension or pipe and hold it to your ear and place it on the air pump , alternator etc. to see where the noise is coming from. Be extremely careful.
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