Symptoms of Failing VANOS Piston Seal in Your BMW

BMW vehicles are known for their power and stamina, which comes from their exquisite design and engineering. Each year, manufacturers take into account the difficulties that their clientele experience with new models, attempting to implement strategies and new designs to tackle the deficiencies their drivers tend to experience. Although BMW vehicles are impeccable as far as engineering goes, sometimes the designs can lead to problems when it comes to performance.

One element of design that has remained a challenge for BMW vehicles is the construction of certain seals, or O-rings. This is especially true when it comes to the VANOS system. VANOS is an engine component that addresses variable valve timing issues. VANOS was introduced due to BMW performance issues, but has wound up causing some BMW drivers to experience other problems as a result. In this article, we’ll go over some of the basic functions of the VANOS system, possible symptoms of system failure, and what you can do to help repair the issue affordably.

What is a VANOS Unit?

The VANOS unit controls the rate at which your BMW engine’s intake valves open, designed to enhance how the car performs, particularly during idling. Unfortunately, the VANOS component is equipped with piston seals, or O-rings, that are prone to early corrosion. After researching the issue and finding the source of the problem, BMW, along with other automotive shops who have seen the same issue come up in their shops, have found that the component makeup of the piston seals, or O-rings, does not stand up well to the intense heat and chemical exposure inside the engine. These piston seals tend to expand and contract significantly and frequently, leaving the part susceptible to all out failure in the VANOS system.

This poses a complicated solution to the issue, as the part cannot be isolated and replaced with an OEM O-ring since BMW doesn’t manufacture or provide that option. Furthermore, in order to address the problem adequately and fix it for good, other seals and VANOS parts must be removed and replaced to avoid further damage to the system. Automotive shops have had to get somewhat creative in the event of a VANOS system failure; they sometimes have to have somewhat custom-made seals fitted that are made of different, more durable materials.

Symptoms of VANOS Malfunction or Failure

The most notable symptom of VANOS malfunction or failure is diminished performance capacity, and if you own a BMW, this is especially problematic. BMW drivers come to rely on the power and push that these German beasts embody, and it can be downright upsetting when problems such as these arise—all because of a faulty seal. Power delivery and disbursement is compromised due to this issue, but you might also notice lowered fuel economy and rough idling. Those issues combined are plenty reason to have the problem looked at by a professional auto mechanic.

Why It’s Important to Hire a Specialist for Diagnosis

When your engine begins to malfunction, the car’s computer generates what are known as “trouble codes.” Usually these codes indicate where the problem is being generated, and it gives professionals an avenue for treating the issue. Of course, engine codes tell us something, but not everything—your BMW specialist will need to do a little inspection and digging to make sure they fix the problem, and its effects, accurately. Since the VANOS system functions well beyond the problem with the early piston seal wear, generally BMW specialists know where to go to find the problem. However, this isn’t an easy task; the entire system must be taken out of the engine. This takes BMW-specific skill, expertise, and experience.

What Is the Next Appropriate Course of Action?

In order to fix the failing VANOS piston seal issue, it’s most important that you bring your BMW to a specialist for immediate evaluation. The Bavarian Performance Specialists have helped many BMW clients with this issue from all over the areas of Thousand Oaks, Agoura Hills, Westlake, Malibu, and Newbury Park, CA. We know that using custom parts and stronger materials to fix this problem is the best approach, and we always commit ourselves to finding solutions for our clients that last. Please contact us with any questions about our diagnostic process, or simply schedule an immediate inspection.

BMW M2 Engine image credit goes to: teddyleung.

BMW M6 image credit goes to: bizoo_n.