Strong pressure through oil cap 1.4l petrol Mk 6 Fiesta

[lukezw]

Hello all

I am looking to buy a cheap used car here in South Africa and I looked at a 2008 1.4 petrol Mk 6 Fiesta.

I was pretty happy with the car until I felt the air pressure coming out the engine with the oil cap removed. With the engine running, it felt like pretty strong gusts of air coming out through the oil filler hole.

Is this normal for the car or a sign of a worn engine? Or is it perhaps linked to some fairly simple issue to fix (e.g. PCV valve/hose)?

The car has been readily serviced and done 80 000 miles/130 000 km so I don't think this sounds like particularly high mileage.

Thanks for any help.