I have been rebuilding my 97 4.2 engine for about 2 months now. Pulled the engine last weekend and am in the process of tearing it down. The back driver's side rocker arm and rod had some damage. The rod has pierced its way thru the rocker arm and is stuck there. That's where the rattling noise came from, when the engine was running . I also found a bit of coolant in the oil pan and fortunatly, NO METAL SHAVING or PARTS.

 

On your rebuild, take Ford's recommendation and use only the 5W20 oil, the top end takes the hit with out the recommended oil.

 

Thank you! Royal Purple 5w20 for me.

 

That sucks man I was in your shoes about a year ago. Everybody that had a 97 4.2 had their engine go out on them.