e46 330d oil separator replacement

Today I replaced the 330d’s oil separator – here’s a quick ‘how to’. Parts:

B11.12.7.793.164 – about ยฃ11 + VAT. Comes with a couple of seals you’ll need too.

Begin, perhaps bizarrely, by removing the cabin filter and assembly tray from the back of the engine below the windscreen. You’ll need to pull all the rubber seals and whizz out 4 star bolts. Don’t drop one of them down onto the belly tray – it’ll cost you a lot of time and make you miss the rugby match you wanted to see.

Remove the air filter cover, and then the larger cover on this side of the engine (temporarily remove oil filler cap). You’ll need a hex attachment and a long extension bar. Note the condition of my air-filter. I would thoroughly recommend changing that item at the same time – I wish I had one in stock!

Next, remove the star capped bolts shown in the photo below. I used an E8 attachment – I think ideally I needed an E6 attachment, but I didn’t have one and the E8 one just about did the job. For clarity: one bolt is under the extension bar that’s in my left hand, the other is silver and in the bottom right corner of the photo.

Here is perhaps a more clear view of proceedings:

The oil separator lives under the circular black casing shown above. Remove more hex bolts, and waggle the assembly out. You’ll need to pull the wiring channel out of the way – it just fits – that’s why those small star headed bolts were removed. Once out you’ll see something like the below – you should recognise the seals that can be replaced with those that came in the separator kit – pull them out using those lovely little lugs and give it all a clean up.

Replace the seals. Engine bay should look something like this (hopefully cleaner).

Prepare shiny new oil separator. Be amazed at how blue the new one is compared with the soggy black outgoing item.

Swap them over.

Inspect giant mess. Put it all together. Marvel at smoke free acceleration! :)

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7 comments so far

  1. John Chadwick on April 16th, 2010 19:49

    Many thanks for this , exactly the same as my engine , E46 330d M Sport Oct 2001 build date.
    Just did this job tonight couple of hours max for me and its the 1st time I touched an engine in 20 years. Popped a new Piper Air filter in while I was at it.

    JC Sth Yorks

  2. Neil Mukerji on April 16th, 2010 22:52

    Hi John,

    Glad the article has been of assistance – great to hear it got you twirling the spanners again after all this time!

    Cheers,

    Neil.

  3. Mark Gooding on June 5th, 2010 15:01

    A great blog, very useful.

    Unfortunately, I’m in the reverse situation. Changed the air filter without having the separator.

    My car is slightly different as well, being a 2004 330 cd.

    MG

  4. Divan on July 9th, 2011 09:47

    Hi there,

    I’ve also got a 330d and I’m trying to remove the part of the engine cover which has the hole for the oil cap but I cant get it off. The whole thing is loose and I have removed the oil cap, but the pipes/wires that go across the engine is blocking me. Am I missing something easy, or what am I doing wrong?

    Kind Regards

  5. Neil Mukerji on July 9th, 2011 10:45

    Hi Divan,

    It sounds like you’re at this point:

    http://cloud.mukerji.co.uk/wp-content/uploads/2010/03/DSC_0129.jpg

    And you’ve undone the two bolts and removed the oil cap. I’m not sure there is anything else to do – unless there’s another bolt towards the cabin, but I’m sure at this stage you can see more than I can! I can’t remember much about moving those cables, but as I can see they remain more or less in place throughout the remainder of my photos I guess you need to seek to find some play to permit the removal of the panel.

    Good luck!

  6. Divan on July 13th, 2011 22:17

    So I actually got the cover off (without breaking anything). The last mechanic did install the new “vortex” type oil separator, so all I did was to clean the EGR valve and put it back.

    By tomorrow afternoon I will know if my feeble efforts made any improvement to the smoking and “hunting” predicament.

  7. Hass on November 11th, 2011 18:14

    Neil

    I can’t thank you enough for this guide, some of the other guides have so many unnecessary steps it would have taken me twice as long. This took me an hour and thats because i had to do it at night with poor lighting. Still managed to drop 2 screws though despite your warning!

    PS any chance of a brake pads replacements guide?

    All the best