Volkswagen Polo - Cooling fan eager to start - demulv

I've recently got a 1.4 TDI 6C (2016) - which seems fine apart from one odd thing. The cooling fan seems to be getting triggered on occasions when it really shouldn't.

It doesn't happen all the time, but there have been several occasions when it's been quite cold outside (3 or 4 deg C), I've started the engine from cold first thing in the morning having sat overnight, and after a few seconds the cooling fan starts. Looking at the coolant gauge it's not even left 0 yet, and the oil temperature on the dash isn't registering any temperature at all.

After I drive for a few minutes the coolant and oil temperature starts creeping up as I'd expect, so I don't think it's a sensor problem. When coolant reaches the half point it stays there.

Then probably about 15 minutes later the fan stops (although sometimes it can take longer).

I've also experienced the fan starting in cold temperatures under little engine load (cruising at around 60mph on the flat in 5th) when it's been -1 outside!

Throughout al of this, I've made sure the air conditioning's been off.

I've taken it to the dealers to be checked out under warranty, and they say no fault code's been recorded (but that's as far as they seemed willing to investigate).

Any thoughts?

Edited by demulv on 18/02/2020 at 10:31

Volkswagen Polo - Cooling fan eager to start - elekie&a/c doctor
Very likely to be part of the dpf regeneration process . The cooling fan will run at odd times , not only when the coolant gets hot .