I have a 03 civic ex replaced radiator thermostat still overheating and the last time it overheated I got a greyish sludge come out of the radiator cap. Can someone help?
if "greyish sludge" is what I think it is, you blew a head gasket when you overheated it. The greyish sludge is motor oil. It sludges when mixed with antifreeze