Temperature Gauge

[zaph]

Driving down from Bristol to Priddy in Somerset today, via Cheddar Gorge, the Lexus performed impeccably this morning.

However climbing the road from Cheddar village through the Gorge, the temperature gauge suddenly rocketed from its usual there-or thereabouts half way bewteen C and H to H and beyond. I did not see the manner in which it arrived there, but glanced down to see where it was, half way up the Gorge. It had been fine this morning before this. Admittedly it is a bit of a climb up, and we were dawdling behind a van struggling to make progress up hill. Once at the top, the gauge fell a little, and by the time we got on open flat road, it returned to its usual position. A simiilar journey home, along back roads, steep inclines and narrow lanes failed to replicate the earlier occurance, too. I was keeping an eye on it. This is the first time the car has done this.

Two questions.

1. Does the temp gauge record real time temperature readings, or, is it pre programmed (as can be with Saabs) to rise to the middle and sit there - not to unduly alarm the driver?

2. So, what would be the cause?

Water level is as should be - the car doesn't seems to use it.

Secondary Radiator fan switch?

Or is this just normal behaviour?

[ManicMark]

Hi sounds like a sticking thermostat to me, It would be the first thing I would change & cheap to do also ( it might not be opening fully)

[zaph]

Hi sounds like a sticking thermostat to me, It would be the first thing I would change & cheap to do also ( it might not be opening fully)

Thanks Mark. Did go through my mind. Noticed heater wasn't working today - no hot air - so I think a flush is in order. I wonder if this would account for a major misfire, when starting from hot, when ambient temperatures are high?