Vikki makes a good point. My car runs at a rock solid 180 degree temp but after I shut it down it will rise to around 220 and if I have recently topped off the radiator it will leave a puddle on the ground (enviromentalists must love me). If you buy an after market temp guage with a capilary tube you could put it under the hood temporarily to get a pretty acurate engine temp. There may even be a spair hole in the intake so you would not need to remove the elec temp sw. Pete