N55 eccentric shaft,valvetronic motor

 Ok this is going to be a long post with a lot of pictures,,,,N55 check engine light on,,,,faults were valvetronic motor and valvetronic won’t reach its limit,,,,performed the test plan,,,operated the valvetronic motor test which passed the test twice,,,but when I started the engine it would fail again ,,,,which tells me all these BMW test are not always correct,,,,lol,,,after more testing it finally said the valvetronic motor and the eccentric shaft should be replaced ok,,,,now the fun started. Here you can see I already removed the fuel injectors and the 3 injector and spark plug stands,,,you have to remove them to gain better access to the valvetronic motor,,,,,also notice the oiler line,,,,you should also replace this at the same time.  Here you can see all the injector and spark plug stands removed. Now the fun started,,,during inspection I found the intake camshaft lobes pitted,,,only cylinder 5 and 6 were pitted,,,,we have no idea what caused this or what happened,,,,now are repairs have changed,,,,we are going to replace the valvetronic motor,eccentric shaft,roller rocker arms and eccentric levers. Here the valvetronic motor which is just a worm gear ,,,,,which can move the eccentric shaft very fast.now here is one of BMW over engineered tools needed to remove and install the the eccentric shaft lever springs,,,,you need this tool to perform this job,,,,there is no other way to do this without hurting yourself.,,,even with this tool you can hurt yourself,,,,,there is a lot of tension on those springs. Here is the new intake camshaft and eccentric shaft,,,,you can see the gear on the eccentric shaft which locks into the valvetronic motor.  When replacing the eccentric shaft there are also 6 needle bearing that have to be replace,,,,the needle bearing and the 2 bearing half shell bearing.this I show you replace them,,,,,they are a split open,,,,you carefully spread them open over the eccentric shaft and make sure they spin freely. Here are all the new eccentric shaft levers. When replacing the levers and the roller rocker arms,,,,they all have numbers on them,,,,,so when you order new ones you need to know what the number is in the engine now,,,,the levers and the roller arms are both 02. Here is the roller rocker arm you can see number 2 stamped in it. . Her is the final assembly ,,,what I also forgot to say the vanos gear is removed,,,,because you will be timing the engine,,,,once your done you hope it starts,,,,you also have to perform a teach in for valvetronic motor ,,,,it performs about 50 test without it failing,,,,if it fails you have to start the test all over again.

This entry was posted in Uncategorized and tagged , , , , , . Bookmark the permalink.

359 Responses to N55 eccentric shaft,valvetronic motor

  1. Henry says:

    Hello please will you help me too, I have bmw x5 with N55 engine. As I see this engine is little bit shi… bmw never ever made so bad engine as n20 or n55 or the V8 twinturbo.. but my question is after replaced MAF and MAP sensors excen. shaft including motor and bearings and caps do all adaptation after, replaced injector 6 for leaking as BMW dealer said which was not true after they diagnostic. the car still has issue. misfire num 3 and 4 (thats why the car had on beginning) of course new BMW spark plug plus all 6 coils. still has same issue. hi pressure after throttle body around 970 plus minus. Runs well only when cold when warm up run like shi… Oil and filter changed also. smoke test done. trying to find the issue over 6 weeks and nothing. the code now is running rich. by me is due not burning all gas on 3 and 4 cylinders. and of course after while come with misfire again still with running rich.


  2. Henry says:

    Hello, do you still help other people? I have 2012 x5 witrh n55 turbo engine. Car had issue with 3 and 4 misfire. We replaced all BMW plug and original Coils no help. Then we replaced eccentric shaft with motor valve cover gasket. NO help. Same issue. The haft and motor was worn out anyway. Than we replaced both temp sensor, MAF and both map sensor. did smoke test passed, did all relearn procedure. Reset all adaptation. It stilklk has 3 and 4 misfire and to run rich but to me is due not burning all fuel and giving more boost after fuel is burn in turbo. We tried also replace injectors no luck. What else could cause misfire on 3 and 4 if car is driving is driving fine no issue. but when i stop on red after like 20 sec get flooded on 3 and 4 and start to have again misfire and run rich.


    • Ok,,,did you perform the teach in after you replaced the eccentric shaft and motor,,,second the only thing that could cause flooded 3 and 4 are the fuel injectors that should be your issue


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.