021-115-311 VW Threaded Oil Filler Cap - Bus & Beetle

Threaded Oil Filler Cap – 021-115-311

Keep your engine bay clean and your oil where it belongs with the 021-115-311 Threaded Oil Filler Cap. This high-quality replacement cap is a critical part of the crankcase ventilation system for later-model air-cooled Volkswagens. Unlike early "twist-lock" caps, this version features a precision-threaded design that ensures a tight, vibration-resistant seal against the oil filler neck used on Type 4 bus engines and late-model fuel-injected Beetles.

Constructed from durable, heat-resistant black composite material, this cap is designed to withstand extreme engine compartment temperatures without warping or cracking. Each cap is engineered to provide a weather-tight seal, preventing oil vapor from escaping and attracting dirt to your engine tin. If your current cap is missing, cracked, or the threads have become stripped, this is the factory-correct solution to maintain proper crankcase pressure.

Detailed Vehicle Compatibility

VW Beetle (Standard):

• 1975, 1976, 1977

VW Super Beetle:

• 1975, 1976, 1977, 1978, 1979

VW Bus (Type 2):

• 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979

Product Highlights & Features

• Direct OEM Replacement: Manufactured to exact Volkswagen factory specifications for a perfect threaded fit on the 021-series oil filler neck.

• Heat-Resistant Construction: Made from premium black composite material that resists chemical breakdown and high engine temperatures.

• Crankcase Pressure Seal: Helps maintain the integrity of the emission system by preventing vacuum leaks and oil seepage.

• Textured Grip: Features a knurled edge design to allow for easy removal and installation during routine oil services.

Technical Specifications

• Part Number: 021-115-311

• Material: High-Temp Composite

• Attachment Style: Threaded / Screw-on

• Color: Black

Installation & Maintenance Tips

• Check the Gasket: A threaded cap is only as good as its seal. Always ensure the internal rubber gasket (111-115-487) is soft and pliable; if it’s hard or flattened, it should be replaced to prevent leaks.

• Hand Tighten Only: To avoid stripping the plastic threads or cracking the cap, always tighten the cap by hand. There is no need for tools to secure a threaded oil cap.

• Thread Inspection: Before installing, wipe the threads of the metal filler neck with a clean rag. Grit or old oil buildup can cause the cap to bind or cross-thread.

• Note on Porsche 914: While the 914 uses a Type 4 engine, the oil filler neck and cap design differ from the VW Bus; please verify your specific filler neck style if working on a 914.

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