Cooling fan running all the time
11-17-2015, 04:33 PM
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Cooling fan running all the time
So I finally got my T belt in and the car running correctly but now it seems like my cooling fan is running constantly. Even with cool temps around 30-40 degrees fahrenheit it still stays on. It has a brand new thermostat too. Is this normal for S8's?
Thanks
Thanks
12-02-2015, 02:27 PM
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Roland
12-04-2015, 12:53 PM
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The HVAC doesn't run the auxiliary fan full time, but the ECU does control it and it runs more often.
I've also found that the fan will run for a few minutes after a cold start (until climate is settled near set temp), and if your trip is short enough it may appear not to shut off.
The only thing that will keep it on all the time is a fault. Try Econ mode as suggested. If that doesn't shut it down, try the trinary temperature switch at the bottom left (when looking from front) of the radiator. I've replaced this switch on both my Audi's (S8 as a precaution when I replaced the radiator).
I've also found that the fan will run for a few minutes after a cold start (until climate is settled near set temp), and if your trip is short enough it may appear not to shut off.
The only thing that will keep it on all the time is a fault. Try Econ mode as suggested. If that doesn't shut it down, try the trinary temperature switch at the bottom left (when looking from front) of the radiator. I've replaced this switch on both my Audi's (S8 as a precaution when I replaced the radiator).
12-05-2015, 05:21 AM
#4
AudiWorld Super User
The HVAC doesn't run the auxiliary fan full time, but the ECU does control it and it runs more often.
I've also found that the fan will run for a few minutes after a cold start (until climate is settled near set temp), and if your trip is short enough it may appear not to shut off.
The only thing that will keep it on all the time is a fault. Try Econ mode as suggested. If that doesn't shut it down, try the trinary temperature switch at the bottom left (when looking from front) of the radiator. I've replaced this switch on both my Audi's (S8 as a precaution when I replaced the radiator).
I've also found that the fan will run for a few minutes after a cold start (until climate is settled near set temp), and if your trip is short enough it may appear not to shut off.
The only thing that will keep it on all the time is a fault. Try Econ mode as suggested. If that doesn't shut it down, try the trinary temperature switch at the bottom left (when looking from front) of the radiator. I've replaced this switch on both my Audi's (S8 as a precaution when I replaced the radiator).
Don't know if it's different elsewhere, but on USA models (both my Audis and all modern VWs I've owned) The electric fan runs 100% of the time when the HVAC is set to "Auto", with the engine running cold engine, hot engine, start to stop, always on.
... the only exception is when the snow flake shows on the instrument cluster (below 40F). When the flake is on, the compressor can not run and neither will the electric fan, unless the coolant passes normal running temp.
I've checked this over the years in virtually every possible situation ... if the engine is running and the HVAC is on "Auto", the fan (referred to in many places as the "condenser fan") is on continuously ... even at 41F outside and the HVAC temp set to HI (above 81F), cold-hot, running it stays on until set to ECON or turned off.
Engine running + Auto = fan on at 40F and above.
Cheers,
Sam
Last edited by silverd2; 12-06-2015 at 04:13 PM. Reason: corrections ... admitting fault :)
12-05-2015, 05:27 AM
#5
AudiWorld Super User
Below 40F outside, do you see a snow flake on the display? If not, you may have a bad ambient temp sensor ... there are 2 of them ... one in front of the radiator (for the cluster display) and another in the fresh air intake.
12-06-2015, 04:15 PM
#6
AudiWorld Super User
PS ... please see edits below about when the fan runs. It occurred to me that engine has to be running ...duh.
...but the rest is exactly what I've observed on mine and haven't seen any VW/Audi that didn't do the same ... auto on (engine running) = elec rad fan on.
Cheers
...but the rest is exactly what I've observed on mine and haven't seen any VW/Audi that didn't do the same ... auto on (engine running) = elec rad fan on.
Cheers
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