Au2ro
Member
That puts my mind at rest a bit that at least if the gauge is not working that the ECU could still be getting the correct data. However, if the climate fan is also playing up that could mean that the ECU is not getting the correct data, which would be bad.The sensor for the temperature that will affect this has TWO circuits and even if the temperature gauge was showing perfectly correctly it still might be the cause. One circuit operates the gauge and the other circuit (in the same sensor (4 wires) feeds the temperature to the ECU to enable it to make decisions on what to do about fuel mixture and also the climate fan etc.
These sender are known to fail.
So, the advice is replacing both the sender and the thermostat first, no matter what previous garages have said about the wiring and the thermostat?My advice is (as I have said) that basically your temperature gauge should be reading 90 when the car is fully warmed. Yours is not.
So the engine is either running colder, which is matching the symptoms you are having, or the sender is broken.
But replacing both at the same time makes sense here no matter what the Fan is doing (in my mind).
Eliminate the less costly and easier to fix options first and since there are many A2s that have a broken sensor and/ or a failed thermostat it will not be a bad thing to "refresh" those anyway. THEN you can have a car that runs at the correct temperature and with the gauge showing that and so then you can look at other causes if you still have the problem.
Eliminating possible and/or likely causes is not a bad approach.
Steve B
That sounds like good advice - your post certainly makes sense to me.
Is it unlikely that there is a wiring issue between the sensor and the gauge then?
I guess the only way to find out is to replace both the sender and the thermostat to make sure that the ECU is getting the correct data and the engine is not running cool.