I replaced impeller,runs 160 at idle,that is where it would stay running wide open before the impeller took a dump. Now runing wide open temp gets up to 180 maybe even hotter but never let it get hotter. Other engine runs 160 . Looking for advice on what might be wrong thanks

Housing could be scored if you did not replace it.

Did you account for all the old impeller pieces?

Back flush the system if you have not.

I thought I got all the pieces. What is the best way to backflush the system. thanks for your help