Water pumps on 2.0L not usually a problem. Operating w/o temp gauge for long could cost you big $$ in the end since there is no idiot light.
Your current problem sounds like faulty lo-speed cooling fan bearing. If you have 2 fans, hi-speed comes on with a/c or extreme overtemp. Lo-speed comes on with normal overtemp when idling in stop & go traffic. Open hood when it happens and check source.
