Originally Posted by Tom K.
When the thermostat went on my E46, the coolant also had to be replaced. But as the symptom of a bad thermostat is an engine that takes forever to warm up, I don't understand why your cooling fan was running so much. In my case, the car was fine in the summer, but ran cold with concomitant poor fuel ecomony (and little cabin heat) when the weather turned cold.
Because it fails open?
no idea? But car warmer up just fine. I didn't always have the fan run like that, did come and go, but did notice it a lot