- Oct 15, 2020
- Reaction score
- New York
- Vehicle Year
- Make / Model
- Ford Ranger
Great thank you.1/2 on Ford gauge is actually 205deg, typo
Start cold engine and feel upper rad hose and heater hose, both will be cold of course
Check both again after 2 or 3 minutes of idling
Heater hose should be warming up
Upper rad hose should NOT be warming up
Heater hoses are on the engine side of cooling system so always have circulation
Upper(and lower) rad hose are on the thermostat side of cooling system so have no flow until thermostat opens
So if upper rad hose is warming up same as heater hose then thermostat is open when it should be closed
Another test, I believe, would be to pump some water into a heater hose and leave the lower radiator tube disconnected from radiator. If water comes down and out, Tstat is open.
I will give this a shot today after truck is cooled completely, and I think with these two controlled tests confirming the same thing, I can start to formulate a plan.