Mini One R56 1.4 Petrol - removing oil cap causes cut out

[AbbeyNormal]

I just wanted to make sure I am not going mad, took a look at a Mini One 1.4 the other day and taking the Oil Cap off caused the engine to cut out. Never seen that on other cars and I thought it indicated an issue with the engine.

Is that normal for a Mini ?

[AbbeyNormal]

Found a very nice 2007 1.6 cooper from a private buyer instead. Full service history. 97k miles. £1200. What can possibly go wrong.

[CarsOrBikes]

cap off on these causes an air leak