The new cyclone separator is part of the crankcase depression limiter and is BMW part no. 11 127 799 367 (for BMW M47 engine). It comes with new gaskets. They cost ~£18 + from BMW dealers. They do not need replacing, perhaps just an occasional paraffin wash.
It is located on the cylinder head behind nos three and four injectors. To gain access remove the plastic engine cover and unplug the injector electrical connections. It is retained by four Torqx head screws. Easy to replace, just dont bother with the L/R "filter" type again.
This question arises so frequently, doesn't it warrant being made a Sticky?
You only need the cyclone bit, part no. .....367, which separates the oil fron the gases going to the inlet manifold and returns it to the sump. The unit also contains the depression limiting valve which, if it is working correctly you do not need to replace.
The O ring seals the cylone to the unit while the other rubbers are replacement gaskets to seal it to the cylinder head.
Hi,
Last week I spoke to a BMW driver about the cranckcase breather. The part is apperently not maintenance free. At about 80.000km/ 50.000miles it should be cleaned. But, that is a lot better than the original.
My TD4 had a service at the main LR dealer 1000 miles before I bought it. When I removed the crankcase filter, a couple of days after purchase and after fitting the EGR bypass, it was obvious from the condition of the filter element that it hadn't been changed for some considerable time so, in my opinion, trusting the main dealer is not always advisable.