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Discussion Starter · #1 ·
Hey guys - got a quaestion for you, I realised that my AC wasn't working so I checked the fuses - they were fine. I suspected that either I had no or little Freon left in the system so I poped into Halfruds this morning to get the EZ charge - DIY kit. I gauged the system - literally no gas, but I recharged it - only noticing that some of the oil residue was on the low pressure valve prior due to recharging - sounds like a leak I kno.

The valve does seem to be leaking a bit after the recharge - so I'm holding my breath if it will equalise when i recap it. Otherwise, kwik fit...



Anyho - when I was performing this task the instructions says that I needed the engine running, and to set the climate control to the lowest setting and max blower - as the engine was running, and the aircon kicking in a begining to cool the car, i noticed that the coolant was rasing nearer to the red zone and it didn'nt stop on the 12 O'clock position - never happened to me before...



So wot's going on? Am I correct that if it approaches to the 12 O'clock - the thermostst should be opening up and diverting the coolant into the rads, and if that is not enough - it will then trip the fan? Well - I notice there are two fans on an M3 the one just infront the engine - which seems to be running all the time on a slow revolution, and another fan just in front of that one - does anyone know the difference between these two and what they cool specifically?



Is my stat stuck on closed? Although unlikely - if I drive and it cools down, indicating that water is being diverted to the rads - something that the aircon is doing perhaps?



Anyone feel free to chime in please.
 

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Discussion Starter · #2 · (Edited)
Anyway, I seem to have more evidence - it seems that when I drive away - the coolant temp does drop bk to 12, but on a 15 mon standstill the needle does go beyond the second white dot towards the red zone - indicating that my fans are not tripping in - I have checked the fuses, but they all seem fine. Wot is causing the fan not to cut in on time?

I have also spoken to BMW - if the AC is turned on, the electric ones should be also spinning - so obviously something has nackered - oh well, specialists then
 

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yes your electric fan should cut in with the a/c compresser running.with the engine off try turning the fan blades by hand....bet they are stiff if they turn at all
reckon its time for a new fan.
while you are under there...start the engine and see if you can stop the other fan running (use a rolled up paper ;) ) because your viscous coupling may have gone
 

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Discussion Starter · #4 ·
Gd morning - well, I have tried to spin the electric fan - it seems to be in a gd condition, i.e. no loose bearings and wobble - considering it will not turn on. Could it be a sensor that has gone for it not to trip? If so, where is this sensor located and do you know roughtly how much it is to replace? In regards to the viscous fan, i guess it will spin freely when it is started up cold so there is v. little resistance to it until the engine is warmed up and the clutch fully engages and spins at engine speed?
 

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afaik the leccy fan is controlled by the ecu...if the water temp sensor is high it cuts in...if the aircon is turned on it cuts in.
have you checked your fuses?
viscous coupling should be checked with the engine up to temp...as you've implied :)
 
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