have just got my series 3 running but have a few queries regarding engine tempature first thing temp gauge not working and i can t find the sender and secondly top half of rad gets hot but bottom stays cold i have changed all the hoses and the stat i dont want to let it run for ages as i cant tell how hot its getting have drained water several times and it seems clean it is a original 2.25 deisel is this just a result of a constant fan or do i have a blockage