hey guys!!! i've had the same problem all winter and now i'm really getting pissed!!! my car just won't heat up!! though it was the thermostat so i take it off put it in boiling water and it seem's like it works just fine!! so bleed the system again!! and then i realize that the fan go on when the temp gage goes higher than (little lower than quater) and then it drops back to cold!! and i forgot to say this is when i press the pedal to the metal!! otherwise it stays at C= cold! so i though of the fan switch i replaced it and the same thing happen!! if i unplug it and REV it up for a long time it gets to normal temperature but as soon as i start to drive it temp drops again even with the fan switch A(cause there is 2)unplug! the other fan switch turn on the fan at the exact good temp(normal operating temp).. so i'm thinking of 2 possibilities 1- the gage sensor doesn't work properly but it doesn't make sens cause i see the temp gage go up and down all the time and the 2nd fan switch turn the fan on at the exact temp of a normal engine operation! 2- I DON'T KNOW!!!! please send me idea or whatever !! would you change the thermostat anyway see if there'S a difference??? i though of placing cardboard in front of my RADiator but that sucks!!! it was working properly and i want it to work properly again!! please no stupid answer !! only ppl who know what there talking about!! thanx!!!