BMW cars are well-made and designed with the driver’s experience in mind. Furthermore, BMW is a brand that continually listens to their customers by implementing designs that address the faults in their previous models, unlike many other vehicle manufacturers. Unfortunately, earlier BMW models are infamous for problems with variable valve timing, which caused serious performance issues for their drivers. This lead to the introduction of the VANOS system, which aimed to remedy variable valve timing hiccups, but ultimately leads to other performance issues instead. More specifically, parts of the VANOS system tend to fail or malfunction, which necessitates immediate repair. It’s important to be aware of the signs that indicate VANOS servicing; therefore, this article is dedicated to helping the reader have a basic understanding of the VANOS system and what BMW drivers can do to prevent problems from arising.
VANOS and its problems in a nutshell
VANOS is an abbreviation for a German-named engine component which was designed to enhance the efficiency of BMW intake performance. This bit of technology is responsible for streamlining engine timing by opening intake valves more efficiently, altering camshaft and drive gear position. Although well-intended, the VANOS system design is far from perfect. One issue with VANOS is that the piston seals tend to wear out prematurely, leading to significant performance deficits. These issues are well documented with the BMW manufacturer, along with BMW forums, enthusiasts, and automotive shops all over the world.
Essentially, the piston seals that are so essential to the VANOS design are not manufactured out of a material that can remain composed under the high heat and stress within the engine, where their consistent expansion and contraction ultimately lead to part failure, which renders the VANOS system practically useless. Furthermore, fixing the issue is not always simple; the original equipment manufacturer part is a replica of the original part, which will eventually run into the same issue as time goes on. Therefore, addressing the problem requires expertise in BMW vehicles and a high degree of automotive skill.
Signs that indicate your VANOS system is in need of repair
Failure of the VANOS system is a widespread issue that drivers have simply had to deal with over the years. It is critical to remain aware of your BMW’s daily performance so that you can pick up on VANOS issues sooner rather than later. These are just a few of the signs to look for in a failing VANOS system:
- Rough idling
- Reduced fuel efficiency
- Lowered performance
- Power deficiency
- Check-engine light illumination
Though the signs of VANOS issues are similar to those of many other part failures, it is important to report these symptoms to your reliable BMW specialist right away – problems with the VANOS system can cause added strain on your engine and lead to more significant issues driving up your repair bills.
Important first steps to take
Any time you notice performance deficits in your BMW, it’s most important to have the problem checked out with immediacy. Because VANOS system issues are usually traced backed to the faulty piston seal, a BMW specialist will know where to look to properly diagnose the problem. Nonetheless, since the symptoms of VANOS failure often mimic other performance issues, a differential diagnosis is always in order. Here are a few first steps you should take to address the problem:
- Hire a BMW specialist to perform a differential diagnosis
- Ask what other options you have besides replacing the seal with the same OEM part
- Attend to other issues a VANOS failure can create
There are a few things you can do to address VANOS problems proactively, including replacing seals before they fail, attending to ongoing maintenance procedures such as routine oil changes to preserve seals longer, and working alongside BMW professionals to anticipate your car’s servicing needs. For over 40 years, the BMW expert here at Pete’s Auto Repair have attended to VANOS issues for drivers from Nob Hill, Pacific Heights, Russian Hill, and San Francisco, CA, and we take pride in our ability to address such issues as piston seal failure effectively. If you’d like to learn more about our shop or our expertise working with BMW vehicles, please call us directly.
* BMW TwinPower Turbo Engine image credit goes to: servickuz.
* BMW M2 image credit goes to: teddyleung.