[GinoE]

I’ve ridden this same path every morning since 2003 - sweltering hot summer days without a problem. Dunno why it became a problem during yesterdays commute.

I tempted fate and rode in again this morning. This time I took a different route – NYS thruway, TZB, Cross County, Hutchison Pky, WSB. The TEMP idiot light came on when I was crawling at the Cross County/Hutchison merge. Luckily for me it’s a down slope, so I did as the mechanic suggested and shut down the bike and coasted for about 5mins until I merged into faster traffic.

I’ve ridden the bike over 600mi since I got it back from the shop without any temp problems. Though I was cruising the entire time, no sitting in traffic. The mechanic purged the coolant and refilled it again from empty.

I suspect the fan sensor.

Fan sensor does not know it’s hot enough to turn on to cool the radiator
TEMP idiot light goes on, Engine overheats
Coolant boils and spews out the overflow

In the past I used to hear the fan come on occasionally, now I don’t hear it at all. The mechanic tested everything OK. I’ll have to re-check it again…