I was about to install an m7 OCC on my 2012 JCW r56 and I had a discussion with the shop foreman at the MINI dealer and he told me not to install it as it confuses the ECU thus changing the pressure inside the crankcase (increase in positive pressure) and eventually cause seals to leak. He said he would not buy one with an OCC installed and to never install one. Been scouring the forums and can't find anything else that seems to agree with this, but now I'm about to return the damn thing. Any thoughts on this? I've read nothing but good things about OCCs but he said he's seen ruined seals caused by these countless times.

 

A mechanic at the MINI dealership once commented on my 2006 MCS saying something like "it is a good thing you don't have an oil catch can on here like so many other folks do". Unfortunately I didn't ask him why he said that.

 

 

Really easy to screw up an OCC install on an N14 and blow a seal or two. However, an N18 OCC should cause no grief --- pretty hard to install it wrong.