Ok,
in Sunday's 'FMD that was hot' (45C) episode, I was powering up the rise on Putty Rd from the Colo river with a car full of kids and the AC at flat chat, and noticed the temp gauge climb above its usual spot. Probably got to 2/3 rather than its usual 1/2
Admittedly, I was lugging it a bit it fourth (2500-3000) - easy to do with the TT torque - but this is the first time I've noticed the temp go up without some sort of problem (low coolant due to leak etc).
Temperatures recovered quickly at the top, and I made sure to use a lower gear for the other bits of the climb, which kept it down to normal levels.
I initially thought maybe the coolant was low -- but on checking it at home, its normal.
Should I be concerned -- have I got a partial blockage or something I need to look at?
Can't say this has ever happened before, and I've driven hundred of miles in that sort of heat (but generally not fanging it up hills with a load).