Running between 90 and 100 is pretty normal. I know that after I replaced most of my cooling system (radiator, thermo, water pump), it still runs between 90 and 100, but I also know that my temp gauge reads about 13 degrees celsius too high. Took it to the firehouse my dad works at and used an IR heat gun and was getting temp readings of around 185*F (85* C) when the gauge was reading about 98. You might want to look into trying to find someone with a heat gun to get more accurate readings.