Hmmm, the fan come on from coolant temp sensor though I think, via the ECU. Presume the gauge in the car is ok? ECU faults tend to be all or nothing.

 

Everything in the car is fine, it gets up to temp and stays at 8bars as long as I am driving, if I get stuck in traffic then I need to turn on the aircon to get the fan working. I did have an airlock in the system which has been bled through and is now fine.

 

Relay?

I presume it does actually overheat if you leave it long enough?

 

if I leave it running without the aircon on it overheats