is there any way to determine if the temp guage on your dash is giving you thecorrect temp of the engine? thanks

 

If your car had comuter control then a scanner would tell what the computers temp sensor is reading. Or use a laser temp gauge and point it at the manifold near the T stat. There would be a difference of about 5 degrees. Or have it running with the cap off and place a thermometer in the radiator or put the probe through the fins of the radiator near the upper hose.