Nice low mileage 124.

I just did mine, on a 1994. Check and see if the bolt going through the tensioner is tight. If loose, it will rattle and you can feel the rattle coming through the water pump. Put your hand on the thermostat housing and you can feel it there. Checking the shock is also advised.

There's a lot of write up about replacing the tensioner. It took me about 2 hours total and did not have to remove the fan and clutch.