Change air oil separator whilst your at it about £14 from BMW so worthwhile and if your consuming any oil it should put a stop to it.
Did plugs and coils on mine don’t recall needing special tools I just did it lol.
When was it £14? I suspect that price has more than double since that time just like how the wheel speed sensors have as they are £174 a pair from BMW lol.
I found this, I assume it's the pipe you are on about? Mine seems to be in solid condition though no visual signs of decay/wear.
https://www.ebay.co.uk/itm/Genuine-...906220?hash=item1ea799feec:g:p9oAAOSwFYJb4tGw