I don't think I can help, but I'll tell you what I know.

If your sohc 3.2 is anything like my dohc 3.2, then you don't have a timing chain. You have a belt. I suppose the belt could start to come apart and slap the plastic cover; but I doubt it would make the noise you describe. Clackety-clack sounds like metal-on-metal contact. There is a hydralic tensioner that sometimes fails. I've never heard one going out, but it's suppose to sound like a rod knocking. Do you suppose that could be it?

Good luck trying to feel anything on the front of the engine with it running. There's not much clearance. Try using a piece of heater hose as a stethoscope to localize the noise. Place one end to your ear and the other end near various components (i.e. timing cover, valve cover, exhaust manifolds, etc.).

Hope this helps. Good Luck.