Water Control Valve 02 QX4

[hussain00]

Can somebody explain to me what is the purpose of the water control valve as shown in the Water Cooling System flow diagram? When does it open and could the engine be heating up really easily if this particular thermostat fails to open?

The FSM seems to not provide much description on this particular part and it's functionality except for what's shown in the flow diagram.

Thanks!

[asnorton44]

Valve opening temperature - 95C 203F
Valve lift - More then 8mm 108C (0.315in / 226F)

[hussain00]

my next question would be, how long does it take the engine to reach the temperature when the 2nd thermostat is suppose to open? Will it ever get to that temperature when it is simply idling??? The reason i ask this is because now with the first thermostat replaced and all the air out from the system, my engine heats up when i had the AC running and i drove it for about 3-4 miles.... There is def. air getting back into the system as well... How long would it take for the engine to heat up if this 2nd thermostat failed to open? or can the heating issue be only because air keeps getting back into the system because of a cracked head?