N20 valve cover cracked

image I know no big deal,,,,a stupid valve cover off of a N20,,,,it was a big deal,,,,we had a lean fuel mixture,,,we first thought we had the typical fuel injectors,,,but spark plugs looked good,,,,we then noticed some oil on top of the valve cover.image I don’t know if you can see it,,,but there was a hair-line crack in the valve cover,,,thank god for a smoke machine,,,,when we smoke tested the valve cover,,,then when we really found the leak,,,,this is the first time we have seen a N20 valve cover cracked.

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37 Responses to N20 valve cover cracked

  1. Brian Clark says:

    Any hints on how to remove. I seem to be hung up on something near the firewall. I double checked and I have all the bolts out and most of the valve cover is lose and free but seems to still be holding on that end is there a pipe or other device back there that is still connected?

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    • You have to remove the vacuum pump at the rear of the valve cover

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      • Brian Clark says:

        That must be it. I did not remove the vacuum pump. Thanks for the tip. It’s tight back there I could not see that well.

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      • Yes ,,,,you will do it by feel,,,the bottom torque screw is the worst

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      • Brian Clark says:

        I was able to remove it by removing both solenoid valves and also the vacuum pump by feeling for the screws it was a size t30 star for the vacuum pump. I replaced the valve cover since I thought that was where the oil leak was coming from (back by the fire wall on the passenger side). Put it all back together and it’s still leaking oil. I am thinking based on location of the oil being above the gasket it’s actually coming out of the vacuum pump itself. There was a small plastic cover on a small valve that seems to have come off. I see some residual oil on it when using a mirror to look back there. I’m guessing oil is leaking past the seals and is being ejected out that exhaust valve.

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      • Check the big vacuum line that comes off the pump,,,check inside the line and see if there is any oil in that line,,,,check the vacuum line that go to the left side of the cylinder head for any oil inside the line,,,,if there is any oil in those lines then the vacuum pump is bad,,,,the vacuum pump is bad internally and pumping oil though the lines.

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      • Brian Clark says:

        There was some oil, also when I took the vacuum pump apart it was full of oil internally. Looks like a bad pump.

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      • Sound like it might be bad,,,,on the plastic cover on the engine,,,is there 2 or 1 vacuum port on it,,,,if there is take off the plastic cover again and turn it to see if any oil comes out of the vacuum ports,,,,if oil does come out then the vacuum pump is bad.

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      • Brian Clark says:

        There is two one is large goes to boost the brakes and there is a small on that’s got a cap on it. The cap was actually blown off and I found it when I took the engine guard off the bottom. I assume when breaking it’s been spitting oil on the exhaust turning the car into an improvisational smoke machine. Thanks for your help on this. I replaced the vacuum pump and will test today,

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    • Did you also remove both solenoid valves at the front of the valve cover

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    • amanda says:

      HI I was wondering if a valve cover leak has anything to do with a oil pan gasket leak. How does the oil pan gasket leak. There is no oil on the ground. Also is there a list of extended service bulletins -example the low emission warranty for 15 years or 150k. Lastly,do you have a list of what components low emission are.

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      • If a valve cover gasket is leaking it could look like the oil pan gasket is leaking,,,,because the oil will leak from the valve cover down to the oil pan causing the problem,,,,I always say start from the top of the engine for oil leaks and clean the area and see what leaks next,,,yes each state has a list of what is covered for low emission cars in their own state,,,no I don’t have a list of what are covered because each state covers something different

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      • I forgot to ask you what type of engine do you have because that makes a difference

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      • amanda says:

        Hi I have a e92, n51 328 xi . Valve cover gasket was leaking ,nasty smell from inside the car while heat was on. They said it didnt leak on anything but I still see a ton of oil. Not sure why I see the oil.

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      • The valve cover is leaking onto the exhaust manifold causing the smell

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  2. Javier Guevara Vico says:

    Hello Andreas
    Just one question: According your experience how long does it takes approximately the replacement of the valve cover gasket in an N20? About 2 hours perhaps? .. More? Less?

    Thanks!!
    javier

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    • For the first time person,,,,depends how handy you are,,,,,but figure maybe over 2 hours for the first time ,,,,,the vacuum pump at the rear of the valve cover can be hard for the first time,,,,you will need some short torque to unbolt the vacuum pump

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  3. Javier Guevara Vico says:

    Hi Andreas.. Thanks for your comment (sorry for my late answer :-)). Just one comment: Referring the vacuum pump, for an N20 mounted in a F30 3er Series, is there enough space to take it out the pump without moving out the engine? .. I was having a look yesterday, and i have the feeling that there is a veeeery little room to take out the vacuum pump.. 😉

    thanks again!
    javier

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  4. Javier Guevara Vico says:

    thanks once more, Andreas!! . anyway, if i am lucky, i will not need to remove the cover nor to replace the gasket: I believe i discovered that the small oil leak appears to be a torque problem: As i could see in the workshop procedure, the torque for the bolts in the cylinder head cover is 9Nm. But i checked the real situation with my torque wrench and i saw that before really arriving to 9Nm, all bolts were able to turn more than 180 degrees!!! .. so it seems that when they mounted the cover about 4 months ago, the torque was not correct and definitely not enough… Therefore I have adjusted the bolts (adjusting from interior to exterior) and now it looks much better.. let´s see .. 🙂
    thanks again!
    javier

    Liked by 1 person

  5. Javier Guevara Vico says:

    hi Andreas… again me .. there is still a small oil leak coming from valve cover 😦 … every X kms, a single small drop of oil comes from the gasket of the valve cover and falls over the exhaust manifold producing this disgusting smell to burnt oil for couple of seconds .. I decided that finally i will replace gasket. I read somewhere by the way that for these composite plastic covers, BMW recommends to change cover+gasket. Is this true in your opinion? In fact i was checking the price of the materials, and if you consider that the part number for the cover includes cover, gaskets, all rings, bolts, etc.. (As i could see at least), the price difference is not so big that if you buy all gaskets and rings and joints separately.

    By the way, i read in the BMW procedure that he main fuel line needs to be replaced (so no reused) if loosen …

    So in summary, would you recommend to change the whole cover and not only the gasket?

    Still miss the time when i could change this gasket in 30 minutes in my old E36 M50 or even more, half of this time in my old Opel CIH engine with its valve cover made in iron, and its cork gasket!!! 🙂

    thanks again!
    javier

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    • Yes if you can replace the whole valve cover with gasket,,,,you do not have to replace the fuel lines, we only replace them if they leak, yes these valve covers are getting harder and harder to replace for the backyard mechanic,,,,,it’s not like the old days on a VW Bug just one big clip holds the valve cover,,,lol

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  6. Johnny Weaver says:

    Crap. Just discovered a spot on my garage floor. Had the timing chain replaced in May. The tech stated he had some trouble with a gasket and had to drive it home overnight to make sure no leaks. First, can you tell me the typical reasons for a small amount of oil leaking under the car might be, in your experience with the N20? And secondly, how much can I expect to pay at a dealership for a valve cover gasket? If that’s it. 2013 328 with 75k miles.
    Thanks in advance for any and all information!

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  7. A_Barnes says:

    bmwtechnician, I had taken my car in to the dealer and he suggested I do a spark plug change (car mileage: 50000 miles).
    1) Is it absolutely required at this stage, car runs fine, has decent gas mileage and acceleration?
    2) If I decide to do it on my own, what are the things to keep in mind? I have read a few scary forums where DIYers have had a lot of misfire issues after replacing the spark plugs themselves, example: https://f30.bimmerpost.com/forums/showthread.php?t=873767
    3) There is confusion on the torque setting as well, 17lb-ft or 22lb-ft? usage of anti-seize, electrical grease, swivel/wobble extension to the ratchet.
    4) Is there some coding that is required after the job is complete?

    All in all, $500 for 4 spark plugs at the dealer seems expensive. Waiting to hear from you, thanks.

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    • Yes the spark plugs are probably worn out,,,if you want to DIY it yourself you just have to take your time,,,,no anti seize or lube on spark plug threads,,,,you do need a racheting with a extension and the a swivel or wobble next to the spark plug socket,,,,torque spec I do by feel because I am old and I have replaced thousands of spark plugs,,,I believe the torque spec is on the spark plug box,,,,don’t use cheap spark plugs use factory plugs please,,,,good luck

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      • A_Barnes says:

        Thank you for your reply bmwtechnician, I appreciate it. I do plan to use the original spark plugs.
        1) I have read that the spark plug gap has to be checked even though the plugs for the N20 are already “pre-gapped” this can cause possible misfires.
        2) Does the “adaptation” need to be reset and can be done by the user? Do additives need to be added to the fuel tank to let the DME relearn control values for the new plugs?

        Where do you see possible issues that a DIYer could run into? Thanks in advance

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      • No you don’t have to reset adaption values when replacing spark plugs,,,,no need for fuel additives,,,,yes you can check spark plugs gaps but they should be good unless someone dropped an spark plugs

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  8. Sukh says:

    Just had this replaced on my 420i 2014 model. 26000 miles. was getting a slight burning oil smell on acceleration. BMW said its a known issue, got it repaired free after dealership got authorisation from BMW hq

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    • Andy says:

      Hi Sukh, did you get a letter of authorization or anything to prove they accepted liability as i have just been given the news of a crack in my cover and i have told them to contact BMW as i am looking at a £700 pound bill.

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  9. FM says:

    BMWTech,

    I followed a mention you made on bimmerfest about the whistling sound made when a valve cover may be cracked. I can’t seem to find your video. Please help. Thanks.

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  10. DV says:

    Hi bmwtechnician,
    Thanks for your awesome website and being so active here.
    I have a question. I have a 2013 F30 N26 SULEV 60k miles. I noticed oil burning smell, looked under the hood, saw oil dripping onto the cat and heat shield, and thought it was a VCG. I took it to the dealership, knowing that it would be covered under the SULEV warranty. The dealership states: “TECH FOUND VALVE COVER LEAKING THROUGH CRANK CASE CHAMBERS IN VALVE COVER.” I haven’t gotten the clarification from the service rep, but I’m assuming this either means that the valve cover is cracked and leaking, or that the leak was simply coming from through the gasket and needing only gasket replaced. In the event that it is the valve cover that was cracked and needing replacement, should there be any other items that I should ask to be inspected to ensure aren’t also faulty as a result or cause of a valve cover crack?
    Thanks!

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    • Nope,,,these valve covers are made of plastic and due to the heat and oil they sometime crack.

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      • DV says:

        Thanks!

        Another quick question, if you don’t mind. At around the same time (or could have been slightly different time), I’ve recently noticed the the Auto Start Stop feature (MSA) is not functioning. I asked the dealership to also diagnose that. They came back stating, “let’s just replace the vehicle battery to see if that fixes it.” At $580 dealer pricing for a batter, I respectfully declined. The A.S.S. feature does not have any effect on the performance or driving functionality of the vehicle, and in fact, I am relieved to not have to deal with the constant start/stop. But, have you experienced this problem with the SULEV’s with that AutoStartStop (MSA) feature? Any where else I could start my own diagnostics?

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      • No I have never had a problem with the autostartstop function not working,,,It could be a battery issue hard to say ,,,,now the autostartstop function doesn’t work every time you come to a stop,,,there are a lot of conditions the car has to meet to perform the autostartstop,,,,I would take care of the valve cover and maybe find a independent to replace the battery,,,,make sure they register the battery

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