110 degrees then 70 (and a flashing light)

[yalan 0]

Driving along today (in my 9A 16v) and watched the temp get hotter & hotter whilst moving in slow traffic.

 

Then it got to 110 degrees and all of a sudden dropped to 70. At the same time the water light started to flash.

 

Couldn't pull off so cut the engine and just started it each time I had to move fwd. Luckily only 5 mins from home. Got home and checked the water levels - still water in the tank but not much sloshing about. It was checked last time I went out.

 

I did leave it on the drive ticking over for 10 minutes but couldn't get it to overheat again - fan kept cutting in to control things. Wierd.

 

Heater matrix was changed recently (if its relevant info)

 

 

 

Anyone have any suggestions as to what to check first?

[mattkh 0]

sticky thermostat