Rad help

hey guys i got a 2000 civic SiR

i had a rad leak so i replaced the rad but now it's over cooling the car is that bad??(it is cold lately)

I'll warm it up take it out drive to work for 30min but the needle stays at the 'C' and only goes up when sitting for a while, but when i drive it will go back down and when the temp reads that low my vtec doesn't kick in (but let is sit and warm up then vtec works) anyone know what it could be? i replaced it with a after market rad not Honda (they wanted like $600 for the rad)

thanks

gary

Replace the thermostat...If you live in a cold weather area look for a thermostat that opens at a higher temp...