this is the first AZ summer for my VX. and I had a similar issue, however, it did not get fixed completely after I replaced fan clutch (Hayden). it still gets to about 70-80% of the gauge while driving in stop-and-go traffic, but goes to normal after few seconds of constant speed driving. My engine is, probably, new, and it is 3.2 6VD1, so I'm blaming the AZ heat.