How Do I Know If My Vanos Solenoid Is Bad?

If you’ve noticed a loss of driveability, decreased horsepower and poor fuel economy, there’s a high chance that your BMW could be experiencing the symptoms of a bad Vanos Solenoid. In this case, it’s important to understand what is going on inside your vehicle and that seeking service from a trained European vehicle mechanic is important to avoid long term damage to your vehicle.

What is the BMW VANOS System?

The BMW Vanos system was implemented in many BMW models starting in the early 1990s, in order to give BMW cars the ability to variably adjust valve timing, which translates to better power and range. This system, in particular, is an important part of any BMW’s engine computer.

The BMW Vanos system is similar to the variable valve timing mechanism that is found in Honda vehicles. Essentially, the Vanos system helps engine timing adjust so that your vehicle can deliver both low-end torque and high-end power, rather than having to settle for one option or the other.

There are different types of Vanos systems which vary depending on your BMW’s model.

Single Vanos

BMWs that use this Vanos system:

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

Dual Vanos

BMWs that use this Vanos system:

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

Dual Vanos with Valvetronic

BMWs that use this Vanos system:

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

There are countless fault codes that could be displayed on your vehicle’s computer that could indicate that there is an issue with your Vanos system. Before discussing how you can spot a malfunctioning Vanos system, let’s first explain how the BMW Vanos system works.


How does the BMW VANOS System Work?

The Vanos system that you likely have in your BMW uses oil pressure to control the position of the intake and exhaust camshafts using a gear on the Vanos actuator and on the camshaft. A long coil of wire wrapped several times, called a solenoid, controls the amount of oil pressure that is applied. By doing this, the solenoid controls the movement of the camshaft gear outward or inward, effectively controlling the timing of the valves.

Symptoms to Look Out For

If you’ve noticed a change in the driveability and performance that you’ve come to expect from your BMW, it might be time to go in for a service. Some symptoms that can indicate that your BMW is having trouble with the Vanos system include:

  • Loss of horsepower and torque
  • Slow reaction to pressing the gas pedal
  • Slow cold starts
  • Limp mode or problems with the car computer after acceleration
  • Decreased driveability
  • Rattling noises or rough idling
  • Inconsistent idling
  • Poor fuel economy
  • General Maintenance for BMW Vanos Systems

Like all parts of a vehicle, general wear and tear occur over the miles. There are two critical points in your vehicle’s life that you should think about seeking service and repair for your BMW’s Vanos System.

50,000 Miles

The Vanos system within your BMW uses seals throughout its construction. As a result, the seals experience wear over time and are typically in need of replacement around 50,000 miles. Around this time, come into AutoScope to see one of our experienced BMW mechanics for repair and service.

70,000 Miles

At this point, it’s highly likely that your Vanos system will need to be replaced but at the very least repaired as a result of general wear on the seals and mechanical parts. Around this time in your car’s life, you should watch out for changes in performance, including low fuel economy, rough idling and low power in your lower range.

How Vanos System Problems Can Be Fixed

Unfortunately, fixing the Vanos system is not commonly done by the vehicle owner itself since the repair is typically quite difficult and requires experience and access to a variety of tools. In this case, the best way to go about fixing your BMW’s malfunctioning Vanos system is by seeking the service of an expert BMW mechanic that uses quality parts to repair, clean and service your Vanos solenoids and overall system.

When you visit AutoScope, you gain access to the expert knowledge of the specific inner workings of European vehicles. AutoScope specializes in service and repair for Audi, Porsche, BMW and Mercedes in the Dallas, Plano, Frisco, Flower Mound, and Irving areas. Schedule your appointment at AutoScope today! Contact us online here.

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