Toyota Repair: Knock after rebuild, ball point pen, main bearings

Question
96 Camry 5SFE 4Cyl Auto
Rebuilt engine but knocks. Isolated noise to be near the lower wall of the number 1 cylinder wall. All bearings were plastigaged during rebuild and standard sizes were appropriate. Crank micd within specs and only polished.  Found main bearings have grooves around the inside center of the bearings of #s 1,2&3 that a ball point pen would fit.  Replaced main bearings but same result.  I dont think thats the knocking but maybe a symtom of another issue. Any thoughts on next steps to take?

Answer
David,

Is this Camry engine use a counter balance shaft under the crank? I would remove it from the engine and check to see if your noise goes away. It won't hurt anything to run it without the counter balance just may vibrate more. Otherwise it sounds as if you have a connecting rod out of round. Did you have them checked or re-sized?