Hey mate....that sounds normal to me. During stop and go driving, when the temp reaches a certain reading ( ?? not sure, but it is over 200F) the fan will come on....then cool the water temp, bringing it below the turn-on temp, thus shuting off the fan....this will repeat especially in stop and go driving.
One thing you could do...and I have seen it posted..... install a by-pass switch to turn on the fan manually. So when you are in Stop and Go driving...you turn it on for continous running.
High hydrocarbons and CO... When was the last tune-up ???
Cheers Mate, have a Fosters !! Life is good!
JzJzz...and the Man from Down Under...