406 Hdi (110) Engine coolant temp to high!

[Gazzas86]

Hi Gents,
been looking around the forum for a while which has been really helpful and have decided to register, as im in need a bit of help.
I own a 406 Hdi Glx 1999 (110) version, 2lt Tdi, its a great car and very reliable!, i decided to give it a good clean at the weekend in which included the engine bay, I think i got a bit over zealous with the water and now when i start the car, probably after 2 mins of being started and left stood still, the stop light comes on flashing every 4 secs, displaying the warning engine coolant level too high, at the same time the engine temp display in the dash moves faily quick to go over into the red and bounces around there, I topped up the coolant with water to see if it did anything to no prevail, when the stop lights and warnings come on the engine is no where near warm.

I believe it could be the sensor as i've googled the fault, however i can't find where the sensor is located in the engine bay,

Any help guys would be appreciated

Regards

Gaz