Ran the car to work fine this morning, and out at lunchtime no problems. Get in it to go home and the red coolant light is flashing pretty much straight away. I checked the coolant level last night and it was fine - can't see any leaks either.
It usually runs with the coolant between 80 and 90deg's and the oil temp at 92/94 degrees.
On the drive home the coolant was between 90 and 100 and the oil temp was up to 100/104 at worst but dropped a few times to 94 deg with the red light flashing all the time.
Anyone got any ideas on what to check for first?
I've read the 'temperature sky high' thread on here but don't know where to start with this as the coolant temp isn't sky high.