I went to the dealership to do an oil change on my non-s mini and he told me that I am missing a plate in my oil filter cap and that it'll cost 500 dollars to replace the entire housing with the new one! I scoured online for pictures of this plate and I'm coming up short. I have the spring but the plastic cage is gone as well. Does anybody know what piece the dealership is talking about? Supposedly it presses down on the filter so it can contact the oil valve.

 

I have read that up to production year '04 they had the cage. Mine is an 04 production 12-03 and when I bought at at 50k it did not have the cage. That confuses me because looking at my housing cap I believe I have the new type without the cage.

That being said, I have looked for the cage and they are no longer available (at least I couldn't find any). You will have to buy the whole filter housing with the new type of cap. Going off memory here I think the filter housing is about $275, pretty easy DIY I think.

 

This is a good description of the issue:
http://www.minimania.com/article/254...roblem_-_Hints