I've been told multiple times that new thermostats are just as likely to fail as old ones. According to one manufacturer trainer, "we not only sell you parts; we sell them to you pre-broken".
Try pinching the upper radiator hose for a few minutes. If the temperature comes up to normal, try another thermostat. On some engines, there is a rubber gasket around the outer edge of the flange. Be sure that is in place. If you have a cap on the radiator, watch the coolant start to flow when the engine is started. There should be no flow until the engine is up to proper temperature.
Thursday, March 25th, 2010 AT 11:06 PM