Hi.

 

I have an XJ6 Diversion. It is water-cooled, 4 cylinder. Today on the 15 mile commute to work I noticed the digital temperature reading fluctuating wildly. When I was travelling around 20 mph the temperature displayed 90C. When I stopped at lights the temp displayed jumped within 3 seconds to 108C. The maximum reading is normally 103C when stationary and idling. When I stopped the bike then switched on again, but with the engine not running, the gauge displayed a maximum of 112C and the radiator fan was running very fast. Once on the journey a red temperature light flashed for less than a second. Any idea what the problem might be? I am guessing 1) the sensor is giving a wrong reading, insufficient coolant fluid 3) water pump broken.

 

Clive

Might just be worth flushing the system out before throwing any money on fault finding exercise

I'd check the coolant firat - it may be low.

Might be a knackered stat, which isnt opening when it should [maybe 90ish]. If in doubt replace it.

As above, change the fluid and the thermostat, why? cos it's a cheap fix.