I got BMW E90 325 i 2006 , it show high temprature mark ( yellow then red)
sometimes it dont give that mark , icould drive it all the day and some i just trun on my car and after 10-15 minutes the mark comes.

i have been talk its the electrical water pump my mileage is 80,000 miles , i turned my car on and i sow the pump workin by pumpin back the water to the water box above.

then i thought it my be workin sometimes and others fail , so i waited when the temp marks yellow then i park on the road and senses the water box , it feels cold which declare that the water pump not work ... then i wait tell the fan stops and cool down for app. 10 minutes , then i drive my car with no hugh temp mark ...

please help me i dont want to change my water pump and thermpstat for 800 $ and i`m not sure , knowing that there is no mark on the scanner for pump fail or and thing else.