engine fan

[polish]

HI thank you for that information.   It is definitely the fan coming from the engine and not the aircon cooling fan as this was not in use when I first heard it.  It seems to come on after a few minutes of setting off from home and if doing short distances goes off when the engine is turned off, but seems to be on most of the journey.  Sorry what is the OAT?

 

 

[YarisHybrid2016]

Outside Air Temperature.

Can you get a video?

[polish]

Sorry am I supposed to know the answer to that?

[alan333]

I assume YarisHybrid2016 was answering your question "what is the OAT?" 

[YarisHybrid2016]

Oh sorry...

Yes - you asked "what is OAT", to which I was answering "OAT = Outside Air Temperature".

Are you able to get a video of the problem you're having? e.g. just driving around somewhere, showing how the fan is being noisy?