Need suggestions about what might be making tapping/knocking noise behind water pump area on 1965 Ford 6 cyl. I thought it was water pump - wasn't. Doesn't seem to be coming from pan area - just behind and under water pump. There is a build up of rust in the water jackets but not sure what sound is. Really would appreciate some suggestions of what I can check. I am no expert but can check a few things. Otherwise engine runs ok. Engine is not the smoothest I have seen nor very powerful. Please post back to the thread or even email me if you'd like at [email protected] Thanks in advance.