With the S type 3litre you have to remove the manifold to change three of the plugs. I did this and put it back together using new manifold gaskets. When I started the car. There was a lot of white smoke. I took the manifold off again and it had water in it. What would cause the water to get in there?

 

I did that.

On the rear side of the throttle body there are some smaller hoses. ONE is vacuam, the one right next to it is coolant, and it is more than easy to plug the coolant onto the vac spigot.

I later had to change both O2 sensors (upstream) coz of contamination, lesson learnt.

Just looked at the Silver car, VAC is the top spigot, COOLANT spigot is directly below it.