Is there another way of testing a thermostat in an X-type without having to remove it from the cooling line? My car seem to be running cold and not reaching the normal operating temperature. i suspect the thermostat is permanently open, thus allowing the coolant to circulate through the radiator and oil cooler even when cold--takes a long time (about 10 minutes) for the temp guage to even reach close to midpoint.

Thanks in advance for the response.

 

Love, about the only test that I can think of is to use an infrared thermometer (the kind that you can just point at something and see what temp it is) and then do a temp of the hoses going into and out of the thermostat. The hose leaving the thermostat should rise to 195F and hover right about there. If the thermostat is stuck open, it will only come up to about 160F or so and then stay right there (due to the radiator providing too much cooling).