[user removed]

Originally Posted by darcane

Maybe, maybe not.

I don't know if it's true on all Civics, but on my '01 the factory gauge is all but useless. It has no numbers, just evenly spaced tick marks with one red one at the top. Based on what my Ultragauge reports, normal operating temperature (180°F) is only about 1/3rd of the way up the gauge, when the fan turns on (206°F) it's still less than halfway. When my headgasket blew and it was overheating (~230°F) it finally got to halfway. I have no idea how hot it would have to get to hit that red mark, but I bet the head would be warped.

So, good advice on the thermostat, just be aware that the gauge may give you poor information.

Benz tech bulletins stated their cars could run as high as 256 degrees without issues as long as coolant was 50-50 mix and proper pressure cap (13 psi). Probably lost the head gasket then ran hot.

regards
mech