I have a 2GM20F installed on aH 290 whose impeller was damaged causing the engine to overheat. When I pulled the impeller, BB size pieces where found in the hose runnning into the heat exchanger. After cleaning out the hose, I pulled the face plate off the heat exchanger and found a few of the impeller pieces in the face on the honey comb in the heat exchanger. I cleaned them off. I am not sure if any of the pieces actually made it through the honeycomb structure into the heat exchanger. Is there any thing else I should do to the heat exchanger before I replace the impeller and and restart the engine? Thanks in advance for you advise.