Clicking knocking when I turn the heat on

[brilis]

Morning all,

97 EB with 5.4 and 100K miles. Further testing needed but it seems like my truck will overheat, didn't let it get that far. No pressure in the radiator hose when running. Temp seems to rise over what it usually runs at. I shut it down. When I turn the heat on, I get a wierd knocking/clicking sound by the front of the engine. Kind of like click, click, knock, knock etc. Does it for aoubt 2-3 secs, stops, then a few seconds later starts again. Just wondering what you guys think? Thanks. Brian