Learning from your good selves, THANK YOU ALL, I could not see a definitive answer to the older M57 & newer M57N breather assembly.
3.0d M57 / N E53 PCV crankcase breather oil separator valve.
I changed ours last night from the older Felt cartridge throw away type to the vortex model. Parts were purchased from GSF in Shrewsbury. 12th March 2015.
You do NOT need to buy the whole assembly just the vortex bit. As this includes ALL o-ring & seals see pic. below. You do NOT need to remove the Air filter. I was replacing ours.
OIL TRAP CRANKCASE BREATHER Part No : 013BM0080 Costing £22.62 retail.
http://www.gsfcarparts.com/013bm0080
Here is one on ebay. http://www.ebay.co.uk/itm/BREATHER-FILTER-CRANKCASE-OIL-BMW-E46-E60-E61-E65-E66-M57-M57N-11127799367-/281251434611?pt=LH_DefaultDomain_3&fits=Car+Make%3ABMW%7CModel%3AX5&hash=item417be45073
Simply remove the felt cartridge & discard safely & responsibly. Clean up breather, I used paraffin followed with brake/carb cleaner & let it dry off.
The FULL assembly with the vortex & seals is this BTW. I got both just in case & will return this unused part today.
ENGINE BLOCK BREATHER Part No : 013BM0030 £46.80 retail.
http://www.gsfcarparts.com/013bm0030
As mentioned above you do NOT need to buy the whole assembly at £47 just the vortex bit at £23. As this includes ALL o-ring & seals see pic.
Haggle if buying.
The Standard (Old Style) WHOLE assembly using the replaceable, throw away, might clog-up felt cartridge filter is this.
ENGINE BLOCK BREATHER Part No : 013BM0060 £46.80 retail
http://www.gsfcarparts.com/013bm0060
Again you DO NOT need the whole assembly, unless damaged, if keeping this type, just the replaceable cartridge like this on ebay. http://www.ebay.co.uk/itm/BMW-E46-E39-X5-330D-CRANKCASE-OIL-BREATHER-SEPARATOR-FILTER-11127793164-A758-/201264251911?pt=LH_DefaultDomain_3&hash=item2edc48c407 at £8 near as.
Replacing the soiled cartridge filter with a new one would be a daft idea from all I have read here & elsewhere. IMO. The vortex type oil separator being the common consensus for a long term solution to the adverse effects of pressurisation leading to possible turbo seal failure. If you right click on the picture & "View Image" you can see the whole picture.
Removed Breather top view.
Removed Breather bottom view.
Oil Separator & ALL seals which I fitted to Breather removed from car. Slip the o-ring on to the breather & push the Oil Separator on & re-fit all to vehicle.
Box Label from above Oil Separator.
Engine bay, Injector loom loose & Air box top removed, which others have mentioned does NOT need to come off & is a bit of pain. I was changing the filter to though.
Engine bay wide shot. Dark, raining & no flash apologies. Note all engine covers removed. Washer bottle unbolted (removed low water sensor wire first !) and hung out of the way. Webasto Aux heater bolts & wires removed to allow centre cabin air filter assembly to be removed. This may not be needed if you do not have the little silver fuel-cooling radiator & filter visible bolted to the side of the Webasto heater.
This shows the angle I used to remove the air filter housing lid. It is the same fro re-fit. Again not needed if ONLY changing the Breather.
It occurs to me that there MAY be a case for fitting the FULL kit, opinions please. The circular section on the breather with the nipple & hole, has a spring loaded valve to admit air & pressure equalise. I guess if this, the spring or seal was not good there would be a case for changing it ALL???
I was going to add this to the following thread but did not want to barge in as it were, hence the new post. I hope this is OK & of some use. http://xdrivers.co.uk/forum/index.php/topic,11088.45.html
Cheers,
JMHC
Never anthropomorphise computers. They hate that.