the car working just fine ,but ther was a water leak,i take it to repair center they said that they changed the water pump,now ther is no leak but when starting the car for 20 minute the water inside the water bottle satrt boiling with a voice of air inside it ,i take the air out of motor by putting a lot of water inside the water bottle after diconecting the return water ,car work for 1day then the same problem again,could it would be the water valve (87 c),knowing that the fan is working just fine when the temperture meter reach to half (never reach to red !!!) and the water cooler unit(wher the fan is mounted) is braned new