[The1Ash10]

I have a 2014 435i (M Sport) with ~30k miles. As you would reasonably presume from the relatively low miles, I don't drive the car very much and didn't drive it at all for nearly two months during the state mandated COVID-19 lock down. Unsurprisingly, after nearly two months of not having been driven, when I eventually tried to start the car the battery didn't have enough power to actually start the car. I later hooked the car up to a NOCO charger/maintainer and after the battery is registering a full charge it starts without a problem; however, I now have a CEL that wasn't there before. I have pulled the codes using the BimmerCode app and I'm getting code 135808 - valvetronic actuator, position sensors, electrical: malfunction. I've also noticed a clicking sound from engine bay (YouTube video of someone else's car making the noise below for reference). It doesn't happen everytime I start or turn off the car; maybe once or twice per week.

I presume based on the my research of the underlying issues that I need a new valvetronic servo motor, but please let me know if you think there is something else I should try first. The servo motor is an expense fix...

[im_an_alien]

If you have access to ista try resetting valvetronic limit positions and/or valvetronic lift. When your battery died the motor may have "forgotten" the limit positions. May be worthwhile to reset all adaptations.

[The1Ash10]

Originally Posted by im_an_alien

If you have access to ista try resetting valvetronic limit positions and/or valvetronic lift. When your battery died the motor may have "forgotten" the limit positions. May be worthwhile to reset all adaptations.

Seems like a good idea. I don't have ista but it looks like a simple download and interface with the car.

[J306TD]

Had this fail on my 335i AH3 in January circa 58K. Needed motor, eccentric shaft and camshaft. Try not to drive it too much as can cause further damage

[The1Ash10]

Originally Posted by J306TD

Had this fail on my 335i AH3 in January circa 58K. Needed motor, eccentric shaft and camshaft. Try not to drive it too much as can cause further damage

Good to know. I hope that's not the issue I'm having.

[yoon_209]

Originally Posted by The1Ash10

I have a 2014 435i (M Sport) with ~30k miles. As you would reasonably presume from the relatively low miles, I don't drive the car very much and didn't drive it at all for nearly two months during the state mandated COVID-19 lock down. Unsurprisingly, after nearly two months of not having been driven, when I eventually tried to start the car the battery didn't have enough power to actually start the car. I later hooked the car up to a NOCO charger/maintainer and after the battery is registering a full charge it starts without a problem; however, I now have a CEL that wasn't there before. I have pulled the codes using the BimmerCode app and I'm getting code 135808 - valvetronic actuator, position sensors, electrical: malfunction. I've also noticed a clicking sound from engine bay (YouTube video of someone else's car making the noise below for reference). It doesn't happen everytime I start or turn off the car; maybe once or twice per week.

I presume based on the my research of the underlying issues that I need a new valvetronic servo motor, but please let me know if you think there is something else I should try first. The servo motor is an expense fix...

Where do I even start... bear with me. my story is long but will give you a better understanding of what you will need to do. As you know valvetronic is bmw's VTEC (variable valve timing) for fuel efficiency.

My valvetronic failed on me doing WOT onto a freeway back in November last year. Car went into LIMP mode and reduced power. Got off the freeway and turned off the car and reset and no codes. I went home to check the codes and same ones. valvetronic position locked, unable to move the lift. After tons of youtube videos and research on the n55 valvetronic on the forums I will explain to what has happened.

valvetronic eccentric shaft actuator has seized. It is unable to move because there is too much resistance on the eccentric shaft particularly on the gear of the shaft and the worm gear of the actuator. There is so much resistance that the actuator cannot move the shaft hence the codes. That is why you are hearing that rapid fire clicking noise. It is the noise of the actuator trying to move the shaft. You will notice that noise upon unlocking the car.

The car will probably run fine and it will feel like there is nothing wrong but what has happened is that you car is now running off the throttle body and the valvetronic system is disabled. You will notice a significant decrease in MPG but car should run 'normal'

So how do you fix it and here are the few options you have. I recommend doing this first and one by one to determine what needs to be replaced.

Best case scenario is that the eccentric shaft actuator is the only issue and you replace it and run the ISTA reset program and it relearns all the positions. This will only set you back up to $1000 for part and labor. I believe the part is a couple hundred and labor to remove the valve cover and blah blah blah. I recommend swapping the valve cover gasket. So you should swap the actuator do the ISTA relearn first. If that doesnt work that most likely you have the worst case which is what I had.

Worst case - the actuator went bad because the eccentric shaft has seized. If you swap the actuator and ISTA doesnt relearn, than most likely the shaft has seized. The shaft seizes because of wear and tear on the gear of the shaft. If this is the case, you will need to replace the eccentric shaft ($1,000), needle bearings on the shaft and all the other gaskets to just access the eccentric shaft. This set me back $3000 for labor and parts back in december.

I hope its not the case but probably more than likely as its a becoming a common issue with the n55 engine. Mind you my car is a 2013 and has 50,000 miles. I am full FBO but i dont think it makes a difference as many people report this issue across all n55 applications.

Good luck.

[J306TD]

Originally Posted by The1Ash10

Good to know. I hope that's not the issue I'm having.

Speak to the dealer about goodwill from BMW. This is a well known issue

[The1Ash10]

Originally Posted by yoon_209

Where do I even start... bear with me. my story is long but will give you a better understanding of what you will need to do. As you know valvetronic is bmw's VTEC (variable valve timing) for fuel efficiency.

My valvetronic failed on me doing WOT onto a freeway back in November last year. Car went into LIMP mode and reduced power. Got off the freeway and turned off the car and reset and no codes. I went home to check the codes and same ones. valvetronic position locked, unable to move the lift. After tons of youtube videos and research on the n55 valvetronic on the forums I will explain to what has happened.

valvetronic eccentric shaft actuator has seized. It is unable to move because there is too much resistance on the eccentric shaft particularly on the gear of the shaft and the worm gear of the actuator. There is so much resistance that the actuator cannot move the shaft hence the codes. That is why you are hearing that rapid fire clicking noise. It is the noise of the actuator trying to move the shaft. You will notice that noise upon unlocking the car.

The car will probably run fine and it will feel like there is nothing wrong but what has happened is that you car is now running off the throttle body and the valvetronic system is disabled. You will notice a significant decrease in MPG but car should run 'normal'

So how do you fix it and here are the few options you have. I recommend doing this first and one by one to determine what needs to be replaced.

Best case scenario is that the eccentric shaft actuator is the only issue and you replace it and run the ISTA reset program and it relearns all the positions. This will only set you back up to $1000 for part and labor. I believe the part is a couple hundred and labor to remove the valve cover and blah blah blah. I recommend swapping the valve cover gasket. So you should swap the actuator do the ISTA relearn first. If that doesnt work that most likely you have the worst case which is what I had.

Worst case - the actuator went bad because the eccentric shaft has seized. If you swap the actuator and ISTA doesnt relearn, than most likely the shaft has seized. The shaft seizes because of wear and tear on the gear of the shaft. If this is the case, you will need to replace the eccentric shaft ($1,000), needle bearings on the shaft and all the other gaskets to just access the eccentric shaft. This set me back $3000 for labor and parts back in december.

I hope its not the case but probably more than likely as its a becoming a common issue with the n55 engine. Mind you my car is a 2013 and has 50,000 miles. I am full FBO but i dont think it makes a difference as many people report this issue across all n55 applications.

Good luck.

Thank you; hugely helpful detail. It's just shocking that something as significant as this happens on modern cars with relatively low miles with such frequency.

[yoon_209]

Originally Posted by The1Ash10

Thank you; hugely helpful detail. It's just shocking that something as significant as this happens on modern cars with relatively low miles with such frequency.

I was quite sad and bummed out when this happened. I was the first person ever with this issue at their specific shop but if you google its all over the internet with people having the same issue.

The main issue is the wear and tear on the gears and he said its due to lack of oil on the gears to property lubricate but its crazy cause i oil change every 7500 miles so idk what the issue was. moving forward im doing oil changes more often but hopefully this issue doesnt occur again.

You may get lucky and only have to change the actuator. good luck. lmk how it goes.

[eluded]

Originally Posted by yoon_209

..... bmw's VTEC

Vtec, yo!

[Muwiee]

I had that same clicking noise for over a year. I have not driven the car much this year, but I hadn't received any direct indications something was wrong with the car. I have 2012 335I with 119k miles. Anyways....... I had performed maintenance on the vehicle and used Rheingold to reset CBS times. I figured I give the car a scan and it popped up with 133E10 Valvetronic system, deactivated, adjustment fault to frequent. I searched internet and found some who performed the adjustment. This only made matters worse for me. The car starting idling rough and then on test drive it would shift horribly. I knew that if not fixed I could destroy engine. The rescan showed codes 134F01 and 134F04(vavltronic, adjustment range, master adaptation outside tolerances; Valvetronic, adjustment range: Fault range check....still no SES lights) I reset all adaptations of the car and deleted the adjustments for the Valvetronic (you start adjustment and when it says deleted you exit out of the function and restart DME; there may be another way I'm not sure this is just how I did it.) Anyways I called a friend over who is BMW master mechanic and was told to try and pull both VANOS solenoids out and clean with brake cleaner. It only takes 30 minutes to pull them out so I figured what do I have to lose. After reinstalling them I started car and got SES light and engine warning----opps forgot to plug in the VANOS. After plugging in and clearing codes I performed a retest and problem is gone. I drove car for 30 miles under normal conditions and then right before I got home, got on it. No issues shifted fine engine was normal and once scanned again no ghost codes or anything saying issue with car. NO clicking noise like your experiencing anymore either. This may work for you. Like others said its important to understand you can brick your engine is this isn't working properly. so be careful.

[Fengzheng1223]

Originally Posted by yoon_209

Where do I even start... bear with me. my story is long but will give you a better understanding of what you will need to do. As you know valvetronic is bmw's VTEC (variable valve timing) for fuel efficiency.

Worst case - the actuator went bad because the eccentric shaft has seized. If you swap the actuator and ISTA doesnt relearn, than most likely the shaft has seized. The shaft seizes because of wear and tear on the gear of the shaft. If this is the case, you will need to replace the eccentric shaft ($1,000), needle bearings on the shaft and all the other gaskets to just access the eccentric shaft. This set me back $3000 for labor and parts back in december.

Good luck.

Hey Yoon, what was the error when ISTA didn't relearn in your case? And by relearn you meant the startup procedure (450 cycles) or just the limits? I am having issue doing the startup procedure as ISTA didn't start counting cycles and told me my engine was not running when it was... it maybe some dumb error I made but was wondering what happened in your case