Hey gang,

I am hoping for a little clarification to make sure that my assumptions about how the thermostat works is actually correct.

Coolant flows out from the very hot engine through the radiator top hose, through the radiator.
Then
Flows out through the little bottom hose.
Reaches the thermostat, when that coolant reaches 82c the thermostat will open fully and recirculate through the engine.

Thanks in advance

 

You got the first part right. Coolant flows out through the top hose.

HOWEVER, because Land Rover really wanted to make sure the heater matrix worked as fast as possible, there are actually three ports on the thermostat. Before the coolant reaches the proper temperature, the thermostat blocks flow from the lower hose and allows flow from the top hose to recirculate back into the engine and through the heater matrix. After the thermostat opens, it blocks flow from the top hose and allows coolant that has flowed through the radiator to circulate to the engine.

 

I do not remember where I got this, but it was from someone in the forum.

 

Follow the arrows...

 

I would follow the arrows if the resolution on the picture was better

 

While coolant temperature is low, thermostat is in bypass mode :
Engine outlet-------------->thermostat-------------->coolant pump suction------------> engine block inlet.

After the coolant rises its temperature, thermostat is "open", bypass path gets blocked :
Engine outlet-------------->radiator inlet--------------->radiator outlet---------->coolant pump suction------------>engine block inlet.

 

Google is your friend.

 

or, glasses.

 

The color coding of this image is incorrect for the heater core lines.

 

Hi. 6 year old post, but does not harm to explain.
Again, in other words : Instead of open/closed; you can think of coolant path selection.
The coolant outlet of the block returns to the block inlet if under the temperature rating of the thermostat. When coolant temperature increases over the rated thermostat temperature, coolant is directed only to the radiator.

Like coolant entering the bottom of a 'Y' -Flows left if under temperature; flows right above temperature, That is the only thing a thermostat does : changes coolant paths and regulates nothing, does not lower coolant temperature in any way. Just switches paths. When the path is towards the radiator, nothing changes while running until engine is shut-off and hours later the coolant temperature decreases under the thermostat rating.