fan clutch

Hello every one ,,, I am new owner of 73 3.0CSI imported from Netherland , car over heats in the city not on highway , I removed the thermostat and problem not solved , radiator looks new ,fan runs but seems to be slow ,, is it water pump ?? belt is tight , any Ideas ?? thanks a bunch ...

Greetings all: I realize this subject has been discussed and resolved for some time now. ( Mr. Potsch 2001 Tech info). However, in the FAQ section, it speaks to a 'relatively" simple conversion/upgrade to the 9 blade, provided the fan clutch is swapped also. My question would...