BMW Repair: BMW520SE, 3 quarters, temp gauge

Question
Hi Don,
       thanks for the reply,wires seem ok,do not know where to look for coolant censor,just been for a run in the car,srarts ok and no noises runs fine till the temp gauge starts to creep up towards the red,so i turned back,car still running ok,except blowning cool air out with heating turned full on but nothing else,back in my drive left it ticking over for a further 10 mins,gauge stayed at 3 quarters on the dial,but ticking over quite and as normal,can you help further.

 Thanks Gerry.  UK>

Answer
Not loosing coolant at all..seems as if the system must be air bound.Bleed the system of air.There might be a bleeder screw on the thermostat outlet...and what about this ticking noise?If it continues I would change the oil and add a bottle of Lucas engine treatment in place of one  quart...stuff works