Do some easy checks before removing the pan. Pull the plugs and turn with a wrench on the balancer pulley. Listen and feel for interference or looseness. Use a boroscope in each cylinder if you have one. If you do not mind cranking, do a compression test on each cylinder. Check the timing marks on t...

My thoughts: Drop the pan and check the main bearing of #2. Maybe all you need is another rod. Used?
volvolugnut

Just bought my first Volvo a few weeks ago: '06 S40 T5. Had lots of known problems, but I was working through them. Suddenly one day huge loud rod bearing knock. You can tell the sound several ways: it's loud. It's terrible sounding. There are metal flakes in the oil. The knocking frequency coincide...