Non SVX engine prob.

Sorry about the non-svx post, but i dont know who else to ask.

The car: 97 grand cherokee 5.2L - 190,000 miles.

Problem: For the first 5 or so seconds after I start it, the valves (i think) make the worst clacking noise. It sounds absolutely horrible. After that point, all goes quiet and the car runs like new.

any thoughts?

-Mike