I have a 2007 case cx240b. Pretty sure we blew the motor in it. Sounded like the turbo went and then the motor ran away. It has a isuzu ah-4hk1x in it. Where is a good place to source parts or find a reman or new motor?
Usually need serial numbers , build codes etc as well as model number when looking for replacement engines. Leaving the risk assessment of rebuilding/ repairing the existing engine, that is on site decisions etc . similar engine used in same class excavator https://www.sumitomokenki.com/products/excavator/sh240-5/ https://www.lbxco.com/240X2.asp The new engine would be tier 4 rated. Could be worth it; if warranty is longer, changed materials in components in the engine build etc etc https://www.isuzuengines.com/Specifications-4HK1.aspx reman might be the most cost effective/ level of risk for the expense incurred for a 12 year old excavator. https://www.isuzuengines.com/pdf/DealerDirectory.pdf
I entered your engine on bing and several sites came up one was MCJ Diesel engine sales ph# 877-268-9140 you can try them they listed the CX210B,C and so on
put an older DT466 in it and call it a day