Hi:

Does the coolant flow FROM the thermostat, into the top of the radiator, out the bottom of the radiator, and into the waterpump? Or vice versa?

Thanks.

 

It should flow from the upper hose into the Block through the thermostat. Then through the water pump to the Radiator.

 

So if the upper radiator hose is hot, then it means the thermostat is NOT opening? Or do I have it wrong?

 

The hose coming from the thermostat to the botom of the radiator should be warm if the thermostat is working.

 

On this 740, this is the coolant system setup:

Thermostat in housing at top of engine - hose to top of radiator - hose from bottom of radiator to waterpump

When I felt the hose between the thermostat and top of the radiator, it was hot. If the coolant should ENTER the engine from this hose based on what Tech said, then this hose should be cool, right? If not, is the thermostat not working?

 

well...cool relative to the rest of the enginge...190 some degrees F is still pretty hot to the touch.

Sorry 'bout that earlier post...i was confusing my cavalier and the volvo again.....

However, if all the hoses are hot off the thermostat (regardless of where they go) then it's working. Weather or not it's working properly on the other hand is another question. Are you overheating?

 

If your upper Hose is really hot and the Bottom hose is cold then the thermostat is not working properly.