What engine do you have?
On my 2.0 litre ecoboost it's got a connector joining to a small bore (around 6mm) black pipe.

 

It's Kuga TF 1.6L Petrol engine.

 

As said there should be a black pipe that connects there. Some models had a blanking cap so I would have a good look for either one.

Not much help but gives you an idea of what to look for.

 

Thanks, I'll have a look around for the pipe in the bay otherwise if I can't find it then I'll have to order a blanking cap for somewhere.

 

@Vedelta can you pop your kuga details in your signature?

 

Done... This particular issue is my sister's 2013 Kuga 1.6L Petrol Titanium Auto.

 

In the UK the bottle is very cheap on ebay but not sure about your country. Still worth having a look 👍

 

Closest photo I could find

 

The small outlet is located underneath the rear bracket slot towards the rear of the coolant reservoir tank. I'm referring to the reservoir tank is a square type shape, not the egg shape.

 

I take it you can’t find a pipe hung down somewhere?

 

Update: Couldn't find any associated pipe but ended up buying a new coolant reservoir tank.

 

Did that tank give you any visual idea what was missing?

 

Just replaced with a new one. All good now. The car apparently didn't have anything else connected to it apart from the usual hoses. The old bottle had alot of hairline cracks and didn't pass the pressure test.

 

Thanks. 👍