Results 1 to 7 of 7

Thread: The dreaded oil separator problem.

  1. #1

    Default The dreaded oil separator problem.

    Many, if not all, modern BMW engines equipped with the plastic oil vapor separator will experience a major failure resulting in non-start or at best, oil blowing all over the engine bay.

    Moisture always mixes with oil, possibly forming a thick whitish mayonaise when condensing (especially when changing oil on long intervals). In cold climates, that white gunk will freeze in the oil separator (PCV valve), blocking the free air passage between the block of the engine and the head.

    If you run an engine dating from the early 1990s (excluding the M20, S14, S38 and M42) it will happen to you. BMW knows about the problem for 15 years. Some BMW technical advisors will even blame the driver for not driving their car long enough and that they are responsible for the condensation...

    Part #1 on the diagram (M52 shown)

    Have your local dealer print out a copy of the SI B11 08 03.
    When your oil separator freezes open - it can cause engine oil hydro-lock and serious motor damage ~ and if frozzen closed - cause a broken valve cover and the leaks you also describe - the above BMW service information bulletin SIB covers E39, E46, E53 X5, E60 5, E85 Z4 w/M54 motor
    Last edited by Lee; 12-18-2007 at 01:03 PM.

  2. #2


    So how long should you drive to car to avoid that problem ?
    Also would this apply to 328i 1998 ?

  3. #3


    Quote Originally Posted by Sempai-mj
    So how long should you drive to car to avoid that problem ?
    Also would this apply to 328i 1998 ?
    Yes it does since you have an M52 engine. I didn't know this was such a big problem but I did notice the techs at work change A LOT of those. And they're a bitch to change too.
    E36 M3/4/5 1997 - (Cosmos Black)
    Bayerische Motoren Werke

  4. #4
    Hiding in the bushes Gregster's Avatar
    Join Date
    Feb 2006
    Pointe Claire QC


    Looks easy to bypass

  5. #5
    Driving Fool johnmdanskin's Avatar
    Join Date
    Mar 2006
    Rhode Island


    My mechanic charges $350 for the bypass. He is on the pricey side and US mechanics seem to make more than Canadians. $350 means about 3.5 hours.

    He told me that you have to drive the car "more than 20min" regularly. If you have a 15min commute to work, you are in danger. If you have a 40min commute to work, you are safe. I try to drive our x5 to boston (60min) every so often. I should get the bypass done, but my mechanic's shop is 90min from my house, so I don't go there every day.


  6. #6


    Europe has two part # for the oil separator valve.

    11 61 7 501 566 is the regular one. Costs 33.1 Euros
    11 61 7 533 400 is for cold climates. Costs 36.3 Euros

    The #400 part is also available in North America for the following cars:
    E39: Details on E39
    E39 525i SEDAN
    E39 525i TOURING
    E39 530i SEDAN

    E46: Details on E46
    E46 320i SEDAN
    E46 323Ci COUPE
    E46 323i TOURING
    E46 323i SEDAN
    E46 325Ci COUPE
    E46 325i TOURING
    E46 325i SEDAN
    E46 325xi TOURING
    E46 325xi SEDAN
    E46 328Ci COUPE
    E46 328i SEDAN
    E46 330Ci COUPE
    E46 330i SEDAN
    E46 330xi SEDAN

    E53: Details on E53
    E53 X5 3.0i SUV

    E60: Details on E60
    E60 525i SEDAN
    E60 530i SEDAN

    E83: Details on E83
    E83 X3 2.5i SUV
    E83 X3 3.0i SUV

    E85: Details on E85
    E85 Z4 2.5i ROADSTER
    E85 Z4 3.0i ROADSTER

    Z3: Details on Z3
    Z3 Z3 2.5 ROADSTER
    Z3 Z3 2.5i ROADSTER
    Z3 Z3 3.0i COUPE
    Z3 Z3 3.0i ROADSTER

  7. #7

    Default test for oil separator

    Mike Miller writes:
    1. remove oil filter car with engine running. Should have moderate vacuum.
    2. If there is a giant whoosing sound and cap is difficult to remove, then replace oil serarator.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts