On a 4.0L, it is where the upper hose connects to the intake manifold. Use 10mm socket to pull 3 bolts. On 3.0L, I believe I recall it is similar.
Its under the steering wheel on the left side
A 1993 Ford Aerostar would have come from the factory with ( 5W-30 )
According to the 1996 Ford Aerostar Owner Guide : ( 5W-30 ) is the preferred oil
On a 1993 Ford F-150 : Follow the top radiator hose from the radiator . Where it connects to the engine is the engine cooling thermostat
A 1993 Ford Aerostar ( 3.0L and 4.0L V6 engines ) came from the factory with ( 5W-30 )
On the 1989 Aerostar it is under the dash near the passenger door.
Spark plug gap for a ford aerostar 3.0 is: .044 (In thousandths of an inch)
On a 1994 Ford Aerostar : Other contributors have previously answered : ( 20 or 21 U.S. gallons )
Owner's manual.My reset button is located on the passenger side, kick panel. (1988 XL areostar)
Follow the upper radiator hose to the engine. The spigot that the hose attaches to should have 2 bolts holding it to the engine block. The thermostat should be located under that spigot.
it is located on the driver side valve cover in the back may be easier to get to from the inside
Its located on the lower radiator hose its called the thermostat housing it comes with a housing and thermostat together u wont miss it