Valvetronic Motor Replacement tips

[d9m13n]

Just posting a few tips on replacing the valvetronic servomotor on 2011+ N55 engine 135i's. (aka valvetronic III, as internally known by BMW)

After diagnosing the valvetronic motor was malfunctioning (clicking noise on activating power locks, many trouble codes thrown by the dme, limp mode, etc) I decided to purchase a new servomotor to solve my problem. The diy's out there are convoluted or missing important info. The best guide to follow is this one https://www.newtis.info/tisv2/a/en/f...-gear/B9qYdYM3
but even this is somewhat confusing and incomplete.

tip #1: put your hood into service position. This means remove the struts on either side and you can move the hood into a fully vertical, AMG-like position that makes working on the engine 10x easier.

tip #2: remove lower firewall cowl on the center and passenger side to create clearance for valve cover removal. Just keep removing plastic on the cowl until you have clear space to remove the valve cover vertically. Its actually very simple to put back together and remove.

tip #3: remove the cover on the white electronics box (pass side of engine bay towards the rear) and pull the wire bundles out of the rubber grommets holding them to the side of the box. Now you have even more vertical clearance to pull the valve cover up vertically.

tip#4: With the valve cover now off, every diy tells you to remove the injectors 1-4 in order to get the injector buckets off so you can remove the servomotor. This is incorrect. Instead of spending 200$+ on special injector removal tools and seal removal tools (they will leak after you remove the injectors and cause misfires or other annoying issues), simply rotate injectors 2 and 4 slightly to the right side to allow clearance to the bolt that the injector plugs are covering. The only special tool you need here is a long shaft t30 torx screwdriver or ratchet attachment. Now you can remove the buckets while leaving the injectors neatly in place.

tip #5: read over the TIS bulletin a few times. Its confusing, but once you have everything in front of you it becomes a lot easier. Have a friend help you with holding the open end wrench on the eccentric shaft while you rotate the shaft using the motor. The knockback from the sprung shaft can definitely take you off guard and youll either lose progress or damage something.

tip #6: reassembly is the opposite of removal!! You will be removing a lot of hardware and parts throughout the engine bay during this process. Takes about 8 hours start to finish (go slow and take your time). Keep all the hardware for things organized neatly. besides that, have fun and enjoy your newly fixed N55!!


I found there is no reason to use ISTA to perform the valvetronic run in program after the replacement, nor is there need to use INPA to reset adaptations in the DME. AS LONG AS YOU MAKE SURE YOU SET THE ECCENTRIC SHAFT BACK TO THE MAXIMUM POSITION after the install, All you will need is a BMW code scanner that is capable of reading and clearing DME codes. Before you turn the car back on after the install, put the ignition ON engine OFF and clear the codes. The car should start back up and perform brand new with all prior codes gone. Remember! The valvetronic shaft resets to the maximum position every time you turn the engine off, as long as the servomotor is functioning properly. That means, when you start the engine again for the first time and the servo is in maximum, the DME knows what to do and can identify its position based on where it should be upon startup.
Maximum position means the gear is facing fully upwards. Youll notice the very last step picture in the TIS bulletin shows the gear facing down, this is very misleading however there is only one way for the gear to orient itself in the max position as the gear is only 180 degrees. The stopper on the gear should be sitting on the max stroke stop that is found on the intake camshaft side of the head.

Hope this helps someone out there! Tedious job, but very rewarding and simple as long as you know what you're doing. Spend 200$ on a new motor and valve cover gasket rather than 1000$ at the dealer or indy shop!