Ingenium engines top mounted oil filter removal
 

The Ingenium engines have top mounted oil filters which just require the plastic cap to be unscrewed to remove the filter element. However this element is attached in some way to the plastic cap and apparently won't just pull off. The new element is identical at each end and doesn't appear to have any sort of clip built into it. Does anyone know how to remove the element from the plastic cap?

Answering my own question (!), I've found that the oil filter does just pull off the cap - but it needs quite a sharp pull to disengage it. The new oil filter just pushes onto the cap until it clicks into place.