3.3L Cylinder head coolant vent plug

[CBP ENGINEER]

1997 Caravan with 3.3L engine. I want to replace the engine coolant in my van. The haynes manual says there is a vent plug in the cylinder head near the thermostat. They even have a nice sketch showing the location of the plug. However, there is no such plug on my van. You are supposed to remove it to get all of the coolant out of the engine, and it will help bleed air out of the system when you refill the coolant. There is a bolt that sits at an angle in the intake manifold, actually there are two, one on each end of the manifold. Are these the vent plugs? If not, where is the plug(s) located?

Another question, I want to install a mechanical water temperature guage. Has anyone done this and where is the best location to install the sensor? I thought maybe I could put it in the angled bolt hole that I described above, but I'm not sure if there is coolant in that location. I could get a tee and install it with the original sensor, but I was hoping there was another location where I could just thread in the sensor.

[96Grand]

Cooling System - Bleeding Procedure

http://www.alldatadiy.com/alldata/AFI~V6593202~C30621~R0~OB0~P3R0H~N/0/41746574/56417202/56417205/56419253/34853741/100411974/34856156/34849420/115648340/56424268/42175473

The cooling system on this engine requires venting by removing the coolant temperature sensor on top of the thermostat housing (http://www.alldatadiy.com/alldata/AFI~V6593202~C30621~R0~OD~N/0/41746574/56417202/56417205/56419253/34853741/100411974/34856156/34856456).

Fill the system with the recommended 50 percent mixture of antifreeze and water until mixture reaches the vent holes, then tighten coolant temperature sensor to specifications. Continue to fill cooling system until full.

[CBP ENGINEER]

Thanks. The Haynes manual said to remove the sensor only for the 3.0L engine, the 3.3L and 3.8L required removing the plug in the cylinder head. Chances are that Haynes was wrong since I don't have this plug in the head. Actually, looking at that picture, the sensor is in the head. I know that mine is located beside the thermostat. So I'll just remove it when I replace the fluid.