VW 01135 Cleaning Requirements for Intake Air, Charge Air and Vacuum Pressure Transmitting Areas

The standard “VW 01135 Engine-mounted parts conveying media - Cleaning requirements for intake air, charge air and vacuum pressure conveying areas”, developed by the Volkswagen automotive company, describes the cleaning requirements for engine-mounted parts that convey air intake, charge air and vacuum pressure and carry media.

Cleaning requirements for parts used in engine manufacturing have become significantly stricter due to increased part loads and certain material modifications required (e.g., lead-free connecting rod bearing shells). Therefore, relevant specifications need to be modified or redefined to further improve quality and customer satisfaction. This standard regulates the protection of sensitive engine components and engine-mounted parts from particulate contamination.

Consequently, to ensure that an economically viable product quality is achieved, the application of this standard must be checked on a part-by-part basis. The target values ​​for the cleanliness requirements specified in this standard constitute a product specification.

The VW 01135 standard is a critical technical standard regulating the technical cleanliness of engine-mounted parts that carry air or create a vacuum. As modern engines move towards tighter tolerances and higher component loads, even the presence of microscopic particles can lead to premature wear or catastrophic failures in sensitive systems.

The VW 01135 standard specifically addresses components used in applications involving media such as intake, boost pressure, and vacuum. These include:

• Intake systems: Manifolds and air ducts.
• Charge air systems: Turbocharger components and intercooler pipes.
• Vacuum systems: Lines and reservoirs used for brake boosters or actuator control.

While general engine parts are usually covered under the VW 01134 standard, the VW 01135 standard is a specific sub-standard for these particular air handling and pressure-sensitive areas.

The VW 01134 standard regulates particulate pollution using two basic analytical methods:

• Gravimetric analysis: Measurement of the total mass of residual particles (typically mg per component or mg/1000 cm³).²).
• Morphological analysis: Determining the size and nature of the largest particles. This is often a more critical metric for intake systems, where a single large, hard particle could damage the cylinder wall or turbocharger vane.

To ensure economically viable product quality, the VW 01135 standard imposes various procedural restrictions on manufacturers:

• Particle size limits: Specific maximum lengths (in µm) for metallic and non-metallic particles. Typically, the limit for parts carrying charged air is set around 600 µm, but this may vary depending on the specific drawing grade.
• Avoiding abrasive materials: Production methods that release highly abrasive materials (such as certain types of grinding, spraying or brushing) are restricted. If used, they must be approved by Volkswagen quality assurance.
• Test procedures: Cleanliness is verified using extraction methods (rinsing, pressure rinsing, or ultrasonic) followed by filtration, as typically specified in supporting standards such as PV 3347.

The VW 01135 standard does not exist in isolation; it is part of a hierarchy of cleaning specifications.

• VW 01149 Basic / General cleaning requirements (basic).
• VW 01134 General engine parts and fittings.
• VW 01135 Intake, charge air and vacuum areas.
• VW 01136 Fuel transport areas (high-pressure systems).
• VW 01137 Coolant and other media transport systems.

In short, the VW 01135 standard defines cleanliness requirements for engine-mounted components carrying liquids or gases (medium), especially in systems operating under vacuum, suction, or pressure conditions. This standard is part of Volkswagen's broader quality framework for suppliers and internal production processes.

The VW 01135 standard applies to engine-mounted components exposed to the following:

• Intake air (intake systems)
• Booster pressure (turbocharged systems)
• Vacuum systems

This standard also applies to components that carry media such as air, fuel vapors, and oil vapors.

Typical parts include:

• Intake manifolds
• Turbocharger pipes
• Vacuum lines
• Pressure hoses
• Sensor housings

The primary purpose of this standard is to control contamination within these systems. This standard is considered important for the following reasons:

• Pollution control: Modern engines are extremely sensitive to particulate pollution. Even very small particles can cause:
  • It can damage turbochargers.
  • It can affect sensor accuracy.
  • It can reduce engine efficiency.
  • It can cause premature wear.

The VW 01135 standard defines acceptable levels of cleanliness to prevent these problems.

• Protection of critical engine systems: The affected systems are as follows:
  • Turbocharger systems
  • Fuel-air mixture control
  • Exhaust aftertreatment systems

Pollution can disrupt airflow or pressure regulation, leading to decreased performance, increased emissions, and component failure.

• Supplier quality assurance: This standard is widely used in supplier qualification. It ensures:
  • The parts delivered to Volkswagen meet strict cleanliness targets.
  • Control of production processes
  • Achieving repeatable quality.

The VW 01135 standard typically covers the following:

• Particle cleaning:
  • Maximum allowed particle size
  • Maximum particle count
  • Restrictions on metallic and non-metallic residues
• Production cleanup:
  • Cleaning processes (washing, rinsing)
  • Drying methods
  • Handling and packaging conditions
• Examination and testing:
  • Particle extraction methods
  • Filtering and microscopic analysis
  • Gravimetric measurement (mass of pollutants)

Tests under VW 01135 typically include the following:

• Washing the component with a defined liquid.
• The accumulation of pollutants on a filter.
• The particles can be analyzed from the following perspectives:
• Size distribution
• Quantity
• Type (metal, fiber, etc.)

The results are compared to the target cleanliness limits defined by VW.

In conclusion, the VW 01135 standard is a critical automotive cleaning standard that ensures the removal of harmful contaminants from engine-mounted components operating under pressure or vacuum conditions. In modern automotive engineering, compliance with the VW 01135 standard is essential for durability, efficiency, and regulatory compliance.

For many years, our organization, with its competent and experienced staff, has been understanding the needs of its customers, providing the advanced testing services they require, and assisting them in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services in accordance with the VW 01135 standard.