2007 S40 2.4i
i bought this car with a blown headgasket and just finished replacing it with a new waterpump and tstat. it was the upper hose that blew and caused it to overheat and blow the gasket.
it runs great now, the temp gauge runs perfectly in the middle (which i think is normal for this car), takes about 5 min to warm up and can idle in the driveway for 30 min....even drove 20 min with the gauge not moving from the middle.
however upon my return trip home on this beatuiful 50 deg day i noticed the temp gauge climbing up a bit...getting about 3/4 of the way but not to the red range. i turned on the heat and the gauge quickly (10-20 sec) drop back to the middle. AC was on and i could hear the compressor short cycling and at that time, i felt the cooling fan spinning slowly, barely moving any air but it was spinning.
i have since tried to duplicate the problem...the AC is short cycling still and the fan isnt coming at all...it still spins free and has 12v going to it...not sure about the trigger wire (not even sure what the signal/triggger wire should read).
i am going to pop in a new coolant temp sensor just because it is cheap and easy but i am not a big fan with throwing parts at things.
how can i let it run for 30 min and take it for a 20 min drive and not have any temp issues and then suddenly have the gauge climb up?
how can i test the fan?
i swear the AC worked the other day when i took it for a quick spin but am now questioning that....the car idle drops pretty good when the compressor kicks in.
could a high pressure AC switch cause the fan to NEVER come on?
i am contemplating bringing it to a shop to hook up the VADIS...which drives me insane to even consider.
please help me figure this out...i thought everything was great last week and the car was finally fixed, now i flustered beyond belief....thanks all!