Remove it from the motor. Put it in a pot of hot water....with a thermometer on hand to see if it "opens" at the correct temp. The same thing applies though...Since you're in there...go ahead & replace it/them., Ken
Hi, Willyme. One way, the way I did it years ago, was to remove it and place it in a pan of cool water along with a candy thermometer. Put it on the stove over medium-low heat and watch it. It should open when the candy thermometer reads 170 to 190 degrees, F. Crude and rustic, but accurate.<br /><br />Red sky at night. . .<br />JB
DANG!!, Ken! I guess I'm not as old fashioned as I thought. I'm not as quick on the draw as I used to be though. <br /><br />Red sky at night... <br />JB
Yeah I would just replace it. I just did mine the funny thing is now water comes out the engine telltale even before the thermo opens? I am wondering if its smaller or something tomorrow I am going to check it out.
I checked mine in some near boiling water and it opened and closed just fine. I didn't have a thermometer to check exact temperature but I think it should do.