This is only a preliminary, starter, answer,an maybe an expert will come along and improve this answer with more detail. Generally, anytime you dissassemble and reassemble anything it is recommended to replace all GASKETS involved. Also, unless your radiator hoses, by-pass hose, and hose clamps have been recently replaced, it is recommended that they be replaced also. Due to your vehicle's age, if these items are "original," it IS TIME to replace these items.
99 Honda passport has a timing belt.
On a 1995 passport it has a timing belt
No it has a timing belt.
Belt
Yes . . . it has a timing chain.
Yes the 2000 passport has a timing belt as does its identical twin the Isuzu Rodeo.
The timing is controlled by the computer. There are no adjustments for the timing
For my 2001 Honda Passport, I paid $420 to have the water pump and timing belt replaced in October 2008.
The water pump on a 1999 Honda Passport is located behind the timing belt cover. The radiator and timing belt have to be removed to access the water pump.
It has a timing belt that must be replaced every 105,000 miles.
i have a 94 Honda passport, my engine is a 3.2L with coil packs. the timing is non adjustable. on the 3.1L the timing indicator is located at the front of the engine by the crankshaft pulley. the timing set is 10-degrees BTDC @ 800rpm. disconnect the set timing connector at the distributor.
The oil pan is underneath the motor on a Honda Passport. You can take the car to a mechanic to have the oil pan changed.