BMW VANOS Explained

BMW Vanos System: Problems, Symptoms, and Repairs

Jake Mayock

Meet Jake

Jake currently owns two N54 powered BMW’s – an E60 535i and E82 135i. Jake has 10 years of experience maintaining, repairing, and upgrading his BMW’s. The 135i features a single turbo Precision 6266 conversion capable of 700+whp; Jake completed the entire project on his own. With over 200 automotive articles published, Jake brings a balance of writing skill, hands-on BMW experience, and technical knowledge to the table.

In early model BMW’s, such as our favorite E30 M3, engine timing adjustments had to be done by hand with a special tool. Variable valve timing is the solution to this problem, and just about every manufacturer has their own technology for it. Variable valve timing allows for timing adjustments to be made electronically and automatically, instead of manually by hand like they had to do back in the day. The end result is a smoother power bank, torque on the low end without comprising power on the high end, and overall just better driveability, smoother idling, etc.

The VANOS system is BMW’s technology that allows for variable valve timing. If you are interested in learning more about VANOS and what to do when it goes wrong, take a look at our Diagnosing a Failing BMW VANOS System Guide.

Table of Contents

How Does the BMW VANOS System Work?

The VANOS system uses oil pressure to control the position of the intake and exhaust camshafts. The system uses a gear on the VANOS actuator and a gear on the camshaft. A solenoid then controls the amount of oil pressure being applied which controls the movement of the cam gear outward or inward, effectively controlling the timing of the valves.

Here is a picture of what the gear looks like on the actuator:

BMW Vanos System

This gear slides inwards and outwards to control timing. When the car is at idle, the gear is fully inward or retracted, and it will begin to slide outward as throttle is given. As you accelerate, the VANOS solenoid begins to close off, which causes the gear to slide outwards. Here is a picture of how that works:

How BMW Vanos Works

If you would rather consume this content via a video, check out our BMW VANOS System EXPLAINED video below:

The 3 Types of VANOS Systems

Since you aren’t yet confused from the above, there are three different VANOS systems used by BMW as the technology has evolved: single VANOS, dual VANOS, and dual VANOS with valvetronic. For the sake of complexity, I’m not going to get into how the systems are different. Instead, lets focus on which cars use which system, and what the engine fault codes are for each.

1. Single VANOS

On the single VANOS system, the intake camshaft timing is the only timing that is variable. This system does not adjust the exhaust camshaft. The single VANOS systems opens the intake camshaft late at low engine speeds to ensure smooth idling and performance. As engine speed increases, the valves open further resulting in increased torque and improved driveability. Think of this as cruising speed. When you put your foot to the floor, the intake valves fully open, resulting in more power and higher performance.

What BMW’s Use the Single VANOS System?

  • M50 engine (’93-’00)
  • M52 engine (’93-’00)
  • S52 engine (’93-’00)
  • M62 V8 engine (’93-’03)

Single VANOS Engine Fault Codes

  • P1519 (BMW 212 0xD4)

This engine fault code means that the VANOS system does not have enough (or any) travel. In most cases, the code is triggered by incorrect camshaft timing. Oftentimes, the code pops up if you have just replaced your camshafts or upgraded to aftermarket cams. Additionally, the code can also be caused by a short on the VANOS electrical system.

Single VANOS Failure Symptoms

  • Loss of driveability
  • Decreased horsepower and torque
  • Rough idling and sometimes a rattling noise
  • Poor fuel economy

How to Diagnose and Repair a Failed Single VANOS Unit

If you are experiencing rough idling you can unplug the electrical connector on the VANOS actuator solenoid. If you continue to experience rough idling after unplugging this connection, then it is likely a faulty VANOS actuator.

The only fix here is to rebuild the VANOS actuators using a rebuild kit or to replace the full unit.

2. Dual VANOS

The dual VANOS system controls the valves on both the intake and exhaust camshafts. The camshafts are controlled by VANOS Solenoids. The benefit to controlling the exhaust camshaft is improved emissions, aka less emissions, along with a quicker engine warm up time. The intake camshaft works the same as the single VANOS and opens up as more throttle is given. The dual VANOS is the system used on the infamous N54, and is very prone to failure in these engines. Fortunately repair is a lot easier.

What BMW’s Use the Dual VANOS System?

  • M52 engine (’99-’05)
  • M54 engine (’99-’05)
  • S54 engine (’99-’05)
  • N54 engine (’04-’10)

Dual VANOS Engine Fault Codes

  • P1520 – camshaft position actuator
  • P1523 – camshaft position actuator
  • P1397 – camshaft position sensor circuit (this can be caused by a faulty sensor. If you’ve replaced the sensor and still get it, then it is the solenoids)
  • 2A82: intake camshaft (solenoid)
  • 2A87 exhaust camshaft (solenoid)

The 2A82 and 2A87 fault codes are guarantees that your solenoids have gone bad. The “P” fault codes are commonly caused by VANOS failures, but can also be caused by other things such as the actuator or a sensor.

We recommend replacing your solenoids if you are getting any of these codes. Replacing the VANOS solenoids is a relatively easy DIY. These things tend to get gunked up and go bad around 50,000 miles, and are commonly operating well below 100% by the time you hit 70,000 miles. Replacing them should restore low-end power and improve fuel efficiency, even if you aren’t getting any fault codes.

Parts for N54/N52 VANOS Repair

We recommend the Febi Solenoids if you are going to do a DIY repair and looking for a good budget option. If you want a pricier but top quality brand then we recommend Pierburg. They are about half the cost of the Genuine parts and in our opinion are better as the Genuine ones fail frequently. URO is going to be the best budget option.

Buy Here: N54/N52 Vanos Solenoids

Dual VANOS Failure Symptoms

  • Loss of torque and power in the lower range
  • Hesitation or slow reaction time when you press the peddle
  • Idle hiccups or a constant rough idle
  • Slow cold starts
  • Limp mode after acceleration

How to Diagnose and Repair a Failed Dual VANOS Unit

Unlike the single VANOS which usually needs to be fully replaced or rebuilt, the majority of the time only the solenoids need to be replaced. One additional option is to try to clean your solenoids, which is a simple process but is only a temporary fix. If you want to try to get a little more life out of your solenoids and save money on the front end, then I recommend trying to clean them before replacing them. There is a good DIY for that here:

If you are going to replace your solenoids you can use the same DIY and just pop the new ones in vs. cleaning and putting the old ones back in.

3. Dual VANOS with Valvetronic

VANOS adjusts the valve timing, or when the valves open and close. Valvetronic is responsible for adjusting valve lift, which is how open the valves are. By combining the two together, you get optimal performance and driveability, increased horsepower, improved fuel economy and better emissions. Valvetronic also negates the need for a throttle body. VANOS and Valvetronic work together and are both controlled by the ECM and powered by engine oil pressure.

What BMW’s Use Dual VANOS and Valvetronic?

  • N52 engine (‘2004-‘2010)
  • N55 engine (’09-‘Present)
  • N62 engine (’04-’10)
  • N73/74 engine (’05-’15)

Dual VANOS with Valvetronic Engine Fault Codes

  • P0011 – A Camshaft Position: Timing Over-Advanced or System Performance (Bank 1)
  • P0012 – A Camshaft Position: Timing Over-Retarded (Bank 1)
  • P0014 – B Camshaft Position: Timing Over-Advanced or System Performance (Bank 1)
  • P0015 – B Camshaft Position: Timing Over-Retarded (Bank 1)
  • P0020 – B Camshaft Position Actuator Circuit (Bank 2)
  • P0021 – A – Timing Over-Advanced or System Performance (Bank 2)
  • P0022 – A Camshaft Position: Timing Over-Retarded (Bank 2)
  • P0024 – B Camshaft Position: Timing Over-Advanced or System Performance (Bank 2)
  • P0025 – B Camshaft Position: Timing Over-Retarded (Bank 2)
  • 2A7A DME: Variable camshaft timing control
  • 2A99 Crankshaft – Exhaust camshaft
  • 2A87 Exhaust Vanos
  • 2A82 Intake Vanos

Dual VANOS with Valvetronic Failure Symptoms

  • Poor and rough idling
  • Loss of lower range power
  • Cold start issues and noises
  • Engine stalling at idle
  • Hesitation or limp mode under acceleration

How to Repair a Failed Dual VANOS w/Valvetronic Unit

With the addition of valvetronic, repairing and fixing issues is rather difficult compared to the dual VANOS only systems. Fortunately, BMW upped their warranty on the VANOS systems to 10 years for cars with double VANOS and valvetronic. Because of this, there aren’t many DIY guides out there, especially due to the difficulty of repair. If you need to take it to a shop and pay for the repair, at least save some money and buy the solenoids below.

N55/N63 VANOS Solenoids

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  1. On a 2004 545 i, do the Vanos actuators need to be synchronized after removing and putting the same ones back on to facilitate intake manifold removal?

  2. I have a 2006 5 series E60 525i straight 6 cylinder i think it has an N52 engine. Could you tell me what solenoids and or VANOS unit it might have? Very noisy (tapping) on start up, This quiets down and disappears after a run


  3. Hi wondering if u could help me out I have a BMW 1series 2007 with the N45 engine, it started missing at high speed and was showing a airmass sensor, that then changed to a crankshaft sensor and now the cars timing is all off and its reading an inlet sensor. The mechanic has now said the timing chain has prob slipped or the vanos is needing replaced. The car has only done 59000 mls and always been serviced, does this sound ryt my mechanics quoting thousands but he doesn’t know for sure any ideas? thanks

    1. Hi John,

      It is tough to say indefinitely, but it sounds like the VANOS solenoids may be the culprit. No offense to your mechanic, but I would be concerned being quoted thousands of dollars when he is unsure of the exact problem. Additionally, if it is simply the solenoids then that price is way too expensive. It’s tough to diagnose an issue on the internet so we cannot make any guarantees that the VANOS solenoids are definitely the issue with your N54.

      You can find the solenoids here:

      And a DIY guide here:

      It’s not too challenging of a DIY and a shop really shouldn’t be charging anything more than $200 labor for the replacement. Experienced mechanics should be able to accomplish the job in less than an hour and even inexperienced DIY’ers can probably do it in a few hours at the most.

      Best Regards,

      BMW Tuning

  4. I have a 2001 e46 320i. I’m experiencing an issue that causes the engine to bog and the RPM’s to drop significantly For a few seconds and then they go right back up after. This only happens while driving and my foot is on the gas pedal. It seems to idle fine. What could this be?

    1. Hi Mark,

      Sorry to hear you’re having issues with your 2001 320i. It’s tough to diagnose those symptoms without any codes. VANOS is definitely a possibility. It sounds like the car could potentially be misfiring due to old spark plugs and/or ignition coils.

      Additionally, we are curious to know how much the RPM’s are dropping? If RPM’s are too low for a given speed & gear that could indicate potential transmission issues. This is far from an exhaustive list of possibilities. There are quite a few issues that may display similar symptoms. Best of luck getting it all sorted out.

      Best Regards,

      BMW Tuning

  5. HELLO,
    I was wondering if my 2008 e60 M5 with the S85 v10 motor is included in the 10 year extended vanos warranty?
    the reason I’m asking is because I got that FC 27B6 along with a crap load more codes for almost all my cylinders misfiring with cutout.

    the e60 M5 I believe has the dual vanos with valvetronics if I’m not mistaken but on the service bulletin I read it wasn’t on there.

    thanks for you help.

  6. Hi,
    I have a 2016 528i which I believe is the N20 engine. I have about 80,000 miles on the car and I’m have a rough idle that goes away after driving for awhile. I figured I would try and replace the vanos. Is it possible to just remove the two vanos solenoids and replace them without screwing up the timing or the timing chain, considering the vanos solenoids run threw the cams? Also, do you know what the vanos solenoid bolt size is to remove it? Thanks.

  7. I have a 2005 BMW 645ci. It’s a v8 and the N63 engine., dual canoe with Valvetronic. How many BMW VANOS Solenoid is needed?

  8. Hi,

    Great guide, but I can’t see my engine listed. I have an N43 (4 Cyl e92 2009 320i). Confident the Vanos solenoid/solenoids need replacing but can’t work out if I have one or two.

    Thanks in advance

  9. Ive got a N73 in my Phantom. Im told by my mechanic that one of the crank sensors have faiiled. Are all 4 of the sensors on the rear of the engine? They tell me that 2 of them are right next to each other and easy to get to but the other 2 are labor intensive.

  10. hey, so I have an N54(335), and I was doing a highway run maybe around 140MPH. Whenever I shifted into 5th gear, I went into limp mode, the car was overheating, and so I pulled over to the nearest gas station, and I noticed the breaks were stiff. idrk when happened, but I assume something went wrong with the camshaft and messed up the vacumn. i got code p0012, and after I let the car cool down, i started driving home after about 10 mins i got a low oil pressure warning, so i stopped and waited a lil while and after that i started the car back and drove home. The next day when i started the car it sounded like a diesel engine and it was stuttering but i cant seem to figure out if it was the camshaft sensor or the vanos that went bad or if the camcould have jumped timing. i also got codes p0015 and p052b

    1. any suggestions, or know what mightve happened also the brakes are still stiff at when the engine is at low rpm and when I test drove it the day after the engine was kind of jerking when in sport mode M1

  11. Hi guys. I have a 2011 E90 320i N46N engine. I’m experiencing all symptoms mentioned above. I just can’t seem to figure out which duel Vanos system she’s running. I regularly clean both solenoids and the symptoms slowly became worse. The mechanic where my vehicle currently is with, recommended a Vanos sprocket change and not the solenoids. I can’t find any diffinnitive info regarding this except solenoid replacement.

  12. Hi guys, i have a 2003 e46 n42 1800cc automatic.
    On idle engine can’t stable but un scanner didn’t show error and if on scanner show error fault code 2854 ( VANOS; sensor singnal immplausy) can’t erased but engine stable.
    Thanks you
    Sorry for my bad language

  13. I have bmw 2004 x5 3.0, hesitation, ideling up and down, slow excelaration , but doesn’t do it all the time

  14. I have recently experienced fault warning in the instrument cluster on my 2016 328xdrive, the code is P0015. I then got it diagnosed at the dealer and appears to be the Vanos Unit (exhaust) but not sure. They want to begin by replacing this part and looking further, The car has only 40,000km and is driving very well (no signs of hesitation or lack of power). The proposed estimate is $1900,,,. I do not feel confortable with this, Could it be the cam shaft sensor reading bad signal? Do I start to replace the sensor and see if the fault is still there?

    1. Hi Sebastien,

      The cam sensor is a possibility, but VANOS solenoids are known to become faulty. It’s usually not a common problem until higher mileage, but sometimes the solenoids give out sooner. Very rarely do we hear or come across many VANOS related issues apart from the solenoids. It’s certainly not unheard of or impossible, but I would definitely consider the basics like cam sensor, solenoids, solenoid actuators, etc before moving onto the big ticket items.

      Best Regards,

  15. Hi
    i have e85 z4 n20b20 engine. My problem is that the acceleration of my vehicle is very slowly (0-100km 11seccond). When the measurement is made with the obd device, the ignition of my vehicle seems to be retarded 3000rpm to 6000rpm 4 to 8 degrees, but it does not give any error codes.

  16. I have a big problem with my e90 330i 2006 rough idle slow to take off I change all four ox sensors still getting the codes still rough idling

  17. My 2000 528i shows code for cam shaft timing. The warning shows on starting. If I clear the code It remains off…until restart. Engine runs fine. Good power. Oil is all good. Seems to be an error in the startup selftest. Help please!

  18. I have a P2090 code on a 04 BMW 325ci M54. I have already replaced the exhaust vanos solenoid and camshaft position sensor and code is still there. Car dose have bad valve cover leaking and am wondering if I should rebuild the Vanos while replacing valve cover gasket or if it will even fix the P2090 code?

  19. I have a BMW X5 E53 4.4i V8 it has a riddling sound like a chain when is warm,but when I start it in the morning it’s sounds smooth.How can I be assisted?

  20. I have a 2000 323i, that is my daily driver, and like clockwork, after I start it up and begin driving, after 10 minutes without fail, it hesitates for a split second, the traction control light comes on, and there is a total loss of power. It will continue to drive at highway speeds up to around 100kmh, although much more sluggishly. The strange part is, if I pull over to the side of the road or highway, and park it for a minute or so, AFTER shutting it off, when I start it up again, it runs smooth as silk, and will continue to do so as long as the engine doesn’t cool off for too long after parking it. It will run all day without a problem, AFTER it has been re started.
    Any ideas?

    1. Hi Steve,

      After looking into it a little bit, it seems like some other E46 owners have encountered similar issues to your problem. It seems like the first place that most people look is the battery. If the battery doesn’t hold sufficient voltage it can lead to all kinds of strange issues like the one that you’re describing. The battery should test between 12.4~12.7 volts when tested with a voltmeter. If your battery is old or hasn’t been replaced in a long time, that could be your issue. Outside of that, some E46 owners have found that it is an issue with their catalytic converter being clogged, causing excessive backpressure to build up in the exhaust system once the engine warms up. I’ll leave a link to the forum post that discusses that issue further. If you have access to a BMW OBD scanner tool, that would point you directly to the cause of the issue. I highly recommend getting one if you don’t already have one, as it’ll make future diagnostics a lot easier.

      E46 traction light on then limp mode forum post:!-then-quot-Limp-Mode-quot


  21. Hi Austin,

    Thank you for taking the time to respond to my issue.
    As far as the battery being the culprit, I’m fairly confident that it’s not an issue, as it was replaced quite recently with the specified type for that model for a cost of $425, also it has never caused me any grief as far as starting issues or bad connections etc.. I’m not saying 100% that I’m sure the battery isn’t the cause, but with the issue slowly getting more frequent, a clogged cat would seem to make sense.
    At this stage I’ll investigate further and share the results of the outcome, likely after having the codes read by a proper reader.
    Cheers, Steve

  22. Hello, I’m Will and have an issue with my 2005 X3 M54 engine. I have the 0028BC Digital Motor Electronics (DME), exhaust camshaft, stiff fault code. Is there a fix for this DTC? Please let me know.

    Thank you,

  23. Hello, I have a 2011 328i n52, E90 (from what I learned). I believe it has the two vanos. It has a rough idle, shakes aggressively and it dies as I drive but drives smooth. I have changed out almost everything instead of the vanos. Is there anyway you can guide me with a tutorial or any suggestions.

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