A bad intake manifold or manifold gasket can cause water to leak into the oil. Some newer cars have plastic manifolds and they will crack from age.
Assuming this is a 4.3L engine, the upper intake manifold gasket would be between the upper intake manifold and the lower intake manifold.
it is possible that the lower intake gasket is failed. That allows oil to be pulled directly into the intake manifold and burned.
jaguar 2001 Lower Engine Intake Manifold Gasket
The Villager has an upper and lower intake manifold. It is at the top of the engine with the throttle body attached to it.
there is no lower intake gasket, only a front and rear gasket
under the lower intake manifold
I assume it would be the same as my 4.0 L in my 1995 Ford Explorer The fuel rail is a " flat " section between the lower intake manifold and the upper intake manifold
Lower intake manifold bolt 115 in/lb. Upper intake manifold bolt 18 ft/.
If you plan to remove the lower intake manifold, you probably have to remove pwr steering pump indeed. Otherwise it makes a difficult removal/installation.
Stand on the pasanger side of the car with the hood open, the intake manifold in now in front of you. The intake manifold is in two peices; upper and lower, the idle air control in attached to the lower. Look at the left of the lower intake manifold, between the firewall and the intake, its barely visible but you should see some electrical clips, two of the four bolts holding the IAC on, and the IAC itself.
by the lower intake manifold while you are doing this you should replace the intake manifold gasket anyway because it will leak sooner or later.
On the left-lower part of the intake manifold (if facing the motor.) The hose runs underneath the manifold.