[mikesz]

My 99 tended to run hotter than I like. A few weeks ago I replaced the thermostat, water pump, and front engine mount. I had the time and do most of the work myself. Car has 80k on it and in a little over a year I have experienced most of the Boxster GREMLINS! So with that said I took the old thermostat and immersed it in boiling water to see if it opened properly. It opened but not all the way and when I let it cool did not close all the way indicating to me it was not working properly. Since doing the work my temp gauge is much more consistent. I also replaced the engine bay fan. it was binding and blowing fuses. Had the same issue with the 2 front coolant fans. I am glad I changed out my thermostat just for piece of mind and the work wasn't all that difficult. You may want to make sure all the coolant fans are working properly also.