Saturday, 29 June 2013

BMW E90 DIY Rocker / Valve Cover Gasket Replacement

DIY Disclaimer: I hold no responsibility should anything goes wrong when you decided to follow my guide. It’s strictly meant as a reference for knowledge sharing purposes.

2007 BMW E90 N46B20

Mileage: 92k km

Been losing engine oil badly due to leaks and valve cover gaskets seems to be one of the culprit.

Last change was during BSRI period in 2010 ( about 2 years ago) and I figure it may be time to change it. Surprisingly, the gasket price has come down drastically to now the original gasket only RM180.

2013-06-30 00.27.26

Item 2 below is the gasket, it comes in 2 pieces as shown in the following illustration. My leaking culprit seems like the inner piece.

Item 3 & 4 below is the spark plug tube O-rings, only 2 tubes are accessible without removing the Valvetronic motor.

My reference material for the DIY:

BMW E87 & E90 (1 & 3 Series) Rocker Cover & Vacuum Pump

Just follow the above YouTube guide and below are some shots I managed to get my camera man to shoot:

1. Microfilter, its tray and other covers taken out:


2. Need to unplug the Vanos sensor sockets and flip the harness over the engine cover to clear the path for rocker cover remover, also remove the 2 wires from the positive jump start terminal, as advice by the YouTube above. Don’t have any bungee cord with me, but have plenty of raffia strings.. Smile and that’s how I secure the hardness away from obstructing the valve cover.


3. Most of the 16 pieces of size 10mm screws are easily accessible except for the one at the upper left corner in the photo, near the firewall, a bit of back breaking persevere bend-over will get the screws out.. Smile with tongue out

When installing the cover, please use the common cylinder head tightening technique of begin tightening from the centre.


4. A blow up of the above photo seems showing the oil cap gasket is the culprit.. Surprised smile No the valve cover gasket!!


5) Oh.. well..


6) Severe wetness around the Valvetronic motor..


7) Close up on the wetness..


8) Viola! Forgot to pull out the No.1 ignition coil.. Open-mouthed smile


9) 91k km almost 6 years old engine exposed! Smile


10) Sludge-free Smile Ignition coil 2 and 3 not removed. Spark plug tube for spark plug No.4 had to be unplugged from valve cover because the Valvetronic motor is the way when lifting/sliding the valve cover out. Meanwhile you will notice there no gasket sealant applied before. Last job was done by Ingress Auto (Authorised Service Centre). Surprised smile


The following are the spots where I applied gasket maker sealant.


11) The bigger picture.. Smile Many dried leaves near the rubber seals around the microfilter, had to vacuum them out to prevent them from entering my engine after the valve cover been removed.

2013-06-29 08.44.05


I took the opportunity to check the oil separator which is connected to this breather hose. The oil separator is actually a spiral inner cavity plastic device to cool down engine crank case fume / breath and catch the oil to divert it back to the oil sump. It has a  recommended lifespan of about 100k km and start to clog up resulting in breath difficulty to the engine. I connect a short section of garden hose to blow into it. I find no difficulty blowing into it means the oil separator not clogged. So I’m in no hurry to replace my oil separator.. Smile


And this are my ignition coils.. for my future replacement reference.. so looks like it’s a Bosch 0221 504 100  Smile


Another trick I want to show is the oil cap fastener. There’s only 2 metal piece securing the cap to the valve cover and depressing against the rubber gasket within the cap to prevent oil from seeping out. Over time the rubber gasket harden and need replacement, the gasket is not sold separately and a new cap cost RM60. To prolong the life of the cap, I press the 2 metal fastener against the gasket as per the direction shown below. This will result in a tighter seal to prevent oil from seeping out.


Also I saw the the oil cap gasket like leaking..

2013-07-05 07.57.00

So I pry out the oil cap gasket to check its condition.. notice the pressed marks below, the rubber gasket still soft, so I flip is around and reinstall it. Now monitoring my oil level, so far so good. Thumbs up


Thank you for reading and please provide feedback or query if any.. Winking smile


  1. Daring ahh you DIY. Tabik!

    1. Scared also.. but exciting ma.. like main mercun.. :p Calculated risk la.. wife is away so I have 4 days to rectify whatever hiccups there is.. including having it towed to the workshop if I really screwed up.. :)

    2. i tried to flip around the oil cap's rubber. lets monitor for a day's journey, and check for any leakage.

      if no, then ur solution is great

  2. Thanks for sharing. I have the same n42 engine on my '02 e46 and my chain guide broke and my chain tensioner is the original one. Your guide helped me discover this issue. Thanks.
    Now my worry is that I will need to do the timing which is gonna cost me a bum. :(

  3. Excellent write up + Clear images.

  4. Thank you very much, mainly specify the places where sealant and exploitations should be put to review other items as the oil breather. Great post

  5. Thank you! Question do you put any specific torque in those headcover screws?

    1. There's no mentioning of specific torque for the head cover screws. They are size 10mm bolts. I just hand tighten until I feel resistance.. just need to make sure similar tightness to all screws.

  6. You are amazing mate!

    Can I ask for my 320 e90 2006( 98km )model?

    Mechanic changed -rocker cover, spark plug, o2 censor, coils- as oil leaks but it still leaks somewhere ( much lesser than previous)

    I can see some drops- not much, just 1-2 drop a day in my car park floor as I put paper on the floor for leakage check.

    I check the oil filler cap, and it leaked. So I flip the rubber ring and hope it will not leak.

    Do you think any other site for leak??

    Can I show you my bmw?

    Many thanks and I will wait for your response!

  7. Hi Eddy, TQ for dropping by. There are quite a few places that can leak.

    Vacuum pump, rocker cover gasket, spark plug tube o-ring, Eccentric shaft sensor gasket, Vanos solenoid o-ring, CCV valve seal, oil filter housing gasket, oil filter cap o-ring, engine sump gasket, and last but not least, flywheel gasket.

  8. Many thanks astroboy!

    Today I found that white smoke from muffler-oil burning- when car is excellerate after idle status.

    Mechanic said, 'better to sell the car'

    Hm.... How can I do
    If I go BMW dealer, it cost heaps? $2-3000 ???

    1. White smoke at 98k km engine mileage? Can't be your piston rings because with proper oil change service, should last at least 200k km. Most of us only replace valve seals. Most workshop recommend top overhaul but actually not required. Total valve seal cost less than RM100 but need to open valve cover and lift up the cams. Your rocker cover gasket u said just replaced not long ago, so should be able to re-fit, if replace again, just another RM180. Labor cost max RM500 to RM600.

  9. Hi astroboy,
    thanks for your comments,
    actually I am stressed from it,
    ( I bought this car 2 month ago and goes well for a month but recently have trouble - white smoke, have to fill up 1litre oil every 5 days.

    Can you recommend any good BMW indie in Sydney area PLEASE?
    I am in Blacktown.


    1. So sorry I'm in Malaysia and have no clue where to service a BMW in Sydney.. do you have a local BMW owners community? Perhaps you can get in touch with them..

      Good luck!

  10. Astroboy, which part of malaysia are you in? Shall we meet up one day? I have the same car.

    1. Wow... Valentine's Day invitation.. LOL! Am in PJ Uptown

  11. I found your tutorials very useful, I have replaced valve cover gasket, water pump, window lifting mechanism, oil housing gasket following your tutorials and saved me a lot of money. Thanks.

    I have found water pump USD $27, rocker cover gasket USD $7.59, window lifting mechanism USD $7 (just plastic part), oil filter housing gasket USD $14.95 and vanos solenoid Viton o-ring $12.99 everything on eBay and everything working fine for about 2 years, except rocker cover which I replaced today, let's see how much it will last.

    1. I forgot to mention that I also replaced front brakes pads USD $20 and rear brakes pads USD $14 following your tutorials, replaced one year ago and everything is working fine.
      Today I ordered cabin filter activated charcoal $17 USD and air filter USD $9