Test Thermostat (84 Cougar 3.8L) January 16, 2012, 07:57:53 AM Boiled some water and poured it into a plastic container.Put in my "old" thermostat(195), left it for around 2-3 minutes and did NOT open.Again boiled water and put in same plastic container.Put in a "new" thermostat (195), left it for around 2-3 minutes and again did NOT open.Am I doing anything wrong or is the new thermostat also bad???======================FWIW AutoZone is selling a thermostat which supposedly stays open if it fails ($13.00).I didn't buy but may be worth considering to stop any potential head gasket issues. Quote Selected
Test Thermostat (84 Cougar 3.8L) Reply #1 – January 16, 2012, 09:35:46 AM Put the t-stat in the water while you boil it, water is probably cooling down while you are transferring it. Quote Selected
Test Thermostat (84 Cougar 3.8L) Reply #2 – January 16, 2012, 02:36:44 PM Yeah, the water will start to boil at different tempetures due to humidity, elevation, air density...It will start to open 10* higher or lower then its rated, and should be full or close to fully open by the rated tempeture. However, expect a 10* change either up or down before it does anything. Quote Selected
Test Thermostat (84 Cougar 3.8L) Reply #4 – January 17, 2012, 09:03:54 AM Thanks all for responses.I know shop manual says boil 50/50 coolant but not enthusiastic about boiling coolant of "any" mixture on my kitchen stove. Will try putting in continue boiling water and leave longer and see what happens. Was expecting an almost immediate opening, obviously not.Still playing with my "NO START" condition after running a couple miles, and then shutting down. Had a three mile walk the other day as failed to start again after a short 3 mile test run. Went back next morning and started fine. Radiator hoses did not seem like they had any water in them and were "to my feel" way way to HOT!. Quote Selected
Test Thermostat (84 Cougar 3.8L) Reply #5 – January 17, 2012, 12:49:56 PM What have you done so far on the no start? Quote Selected