I've finally had it with this stupid thing my car does im gonna try to fix it. as i drive, the temp gauge climbs up to the N (3 gauge cluster) and goes a little higher. however when the OD kicks in the gauge drops to the R or to the M it vary's with speed. at 25 its between O and R, 40 is R, and 75 is M. i dont know what it is, coolant isnt disappearing to my knowledge. when the gauge is way up there by the N, the car blows cool air and then when it goes into OD the air becomes warm. im completely ****ing lost right now.