Hi,

Does anyone know the real temp (not gauge temp) at which the thermal fan is meant to first kick in? Also, what the fan behaviour should be when shutting down.

I'll explain a little more the issue I'm having:

- For the first time, the car is showing above 90 on the gauge
- when turning off the car, the fan often kicks into mega high speed and runs for 2-3mins. Bear in mind the weather isn't even hot yet!
- No engine faults being logged
- The battery is struggling

Here is what I have observed/ruled out:
- waterpump is good. Was replaced <30K ago with a metal impeller version, and has good flow coming out of coolant overflow line
- Both fan speeds (and both fans) work - if I turn aircon on, low speed fan instantly turns on regardless of temp. High speed definitely works and is often on when engine shut down
- With no air-con on, VCDS is showing 105-108 degrees to be the point at which the thermal fan kicks in. A bit high?
- engine warms up within 5 mins - thermostat not stuck open
- engine cools down when thermal fan kicks in. Also cools down once traffic flows - thermostat not stuck closed. Do they have issues where they only partially open?
- it seems to me the thermal fan might not be kicking in according to the temp that VCDS is showing - I understand there is more than one coolant temp sensor, could it be a fault with one of the coolant temp sensors?


Any ideas on what else to check? I hear fan control modules can go, do these symptoms sound like it could be fan control module?