That would be the infamous rattle tick that happens
when the timing belt tensioner loses tension on the
timing belt. Buy a timing belt kit that has the timing
belt, water pump, tensioner, bearings, water pump
gasket and crank seals. You also might wanna
replace the position crank sensor! The Mitsubishi
3.0 V6 is peppy engine but if you don't do the
maitnence you will have problems! I would also do a
tune up, sparkplugs, wires, distributer cap and rotor
and valve cover gasket seals. Replace both upper
and lower hose and thermostat and hose clamps. I
know it sounds like a lot but it's cheaper than buying
a new car or making car payments with full
coverage insurance!