Does the 2005 Chrysler Pacifica have a timing belt or chain?

Your 2005 Chrysler Pacifica uses a timing chain to drive the water pump and other components. This chain will typically last the life of the vehicle, or at the very least, 100,000 miles, without requiring replacement. You will, however, need to keep Your engine lubrication maintained. If You start hearing rattling sounds or other sudden harsh noises, that could be an indication that Your timing chain needs servicing; check if it's coming from the area where the timing chain is connected to the engine camshaft and crankshaft, and if You endeavor it is the chain, take it into the dealer. Unless You're very comfortable around Your engine, this is a job for the pros!