[Zanity]

When I took my basically new still 428i with just 39,000km out of covid storage, there was a lot of rough idling and stalls, i used bimmerlink and got a whole bunch of random codes (see code photos below) so with the help of a friend who was a senior technician at bmw dealership, we found the culprit to be the vanos solenoid actuator (just like the N54 E92 I previously had), heres a quick guide to fix the issue:

- In front of your engine near the top (see first photo), there are 2 vanos actuators (intake and exhaust), you can simply unplug the connectors first to test, use a small flat screw driver to pry the clip towards the front of the car and pull down the connector. Start the car, you will get the "drivetrain malfunction" error on your idrive, which is normal, the car will now use default factory timing only, it won't advance timing and your turbo will be disabled. but if your rough idle / stutter / stall is gone, then you found the problem. If you still have hesitation or rough idling, then it's something else, possibly camshaft sensor or fuel related or MAF.

- WARNING: You can drive with the VANOS connector unplugged, but do not remove the actuator off the engine (like the first photo), if you start the car with the actuator removed, your engine oil will piss all over your engine bay. (No, this didn't happen to me lol, but I thought I should state the obvious.)

- Buy new vanos actuators, search for " VANOS Solenoid Actuator" for your engine, I got mine here: https://www.ebay.ca/sch/i.html?_odkw...+428i&_sacat=0

- To replace them, you will need to have the BMW tool for the hex 10 set, I don't have the tool here so I can't remember which one I used but they come in a complete set that you'll need if you want to work on any BMW. There are only 2 screws you need to remove on each side as shown in the 2nd photo. The rubber gasket may stick to the engine, so make sure you don't double gasket when you install the new one. Do this for both vanos.

- Once you're done, you need to reset the ECU and clear all codes with OBD, I did it with my bimmerlink app, it's also best to reset your transmission as well (power on the car without starting, hold down gas pedal for 20 seconds then turn off car for 2 mins).

- Whole process takes about 10 minutes to do, but at the dealer, it will cost you $400 for each vanos and another $600 for labour plus diagnostic, so it's beyond worth doing it yourself first.

P.S: Cleaning these vanos doesn't help, you might buy an extra week of life, so just get new ones, you can buy just 1 and try to find which of the old ones broke, they don't usually both break at the same time. Both intake and exhaust vanos are identical parts so they are interchangeable. Driving with the vanos actuator unplugged is perfectly fine while you wait for the parts to get shipped, you will only have about 50hp available so try to avoid big hills.

[Pdxway]

Originally Posted by Zanity

So when I took my basically new still 428i with just 39,000km out of covid storage, there was a lot of rough idling and stalls, i used bimmerlink and got a whole bunch of random codes (see code photos) so with the help of a friend who was a senior technician at bmw dealership, he said the most common issue is the vanos timing solenoid (just like the N54 E92 I previously had) so heres a quick guide to fix the issue:

- In front of your engine near the top (see first photo), there are 2 vanos (intake and exhaust), you can simply unplug the connectors first to test, use a small flat screw driver to pry the clip towards the front of the car and pull down the connector. When you do this, you will get the drivetrain malfunction on your idrive, which is normal, and the car will use default factory timing, it won't advance timing and your turbo will be disabled. but if your rough idle or stutter or stall is gone, then this is the problem. WARNING: You can drive with the VANOS connector unplugged, but do not remove them off the engine (like the first photo), if you drive with them removed, your engine oil will piss all over your engine bay.

- Buy new vanos, serach for timing solenoid for your engine, to replace them, you will need to have the BMW tool for the hex 10 set, I don't have the tool here so I can't remember which one I used but they come in a complete set that you'll need if you want to work on any BMW.

- Once you're done, you need to reset the ECU and clear all codes with OBD, I did it with the bimmerlink app, it's also best to reset your transmission as well (power on the car without starting, hold gas pedal for 20 seconds then turn off car for 2 mins).

- Whole process takes about 10 minutes to do, but at the dealer, it will cost you $400 for each vanos and another $600 for labour plus diagnostic for a total of a grand, so it's beyond worth doing it yourself first.

P.S: Cleaning these vanos doesn't help, you might buy an extra week of life, but just get new ones, you can buy just 1 and try to find which of the old ones broke, they don't usually both break at the same time. Both intake and exhaust vanos are identical parts so they are interchangeable.

[ViperaNegra]

Hi,
did you removed both connectors at the same time, or one by one, can i start the car with just one disconnected or it has to be both....?
THX

[Zanity]

Originally Posted by ViperaNegra

Hi,
did you removed both connectors at the same time, or one by one, can i start the car with just one disconnected or it has to be both....?
THX

Hi, you just need to remove one, intake and exhaust vanos have to work together to advance timing, so ECU will disable both when it detects one is disconnected. Typically it seems the exhaust one (the lower one) is more prone to fail.

[cfm56d7b]

This post will undoubtedly save countless dollars (or one's favorite currency) in the future. Thanks for sharing!

[bloodline129]

My 2015 435 does that. It hasn't stalled yet but intermittently on cold starts RPM's surge to 1200 and drop rapidly to a point of stalling (got really close twice that it almost stalled)

It started happening about 2 months ago. My bimmer link app shows no codes tho.

I still got extended warranty so hopefully I can get it addressed when there is codes with it

[Zanity]

Originally Posted by cfm56d7b

This post will undoubtedly save countless dollars (or one's favorite currency) in the future. Thanks for sharing!

You're welcome bud, surprisingly I can't find much info on this DIY anywhere, even on youtube.

Originally Posted by bloodline129

My 2015 435 does that. It hasn't stalled yet but intermittently on cold starts RPM's surge to 1200 and drop rapidly to a point of stalling (got really close twice that it almost stalled)

It started happening about 2 months ago. My bimmer link app shows no codes tho.

I still got extended warranty so hopefully I can get it addressed when there is codes with it

Let me know what they end up finding, my car also didn't throw any codes for a week, then it got worse and all those codes showed up, but none of it was related to the vanos itself.