Description

The Audi Cover (3B0121321) is a genuine OEM coolant expansion tank cap / reservoir cover used in the engine cooling system. It seals the coolant reservoir, maintains proper system pressure, and prevents contamination from entering the cooling system.

This cap is a critical safety component that ensures the coolant system operates efficiently and prevents overheating. It is widely used across multiple Audi models including A3, A4, A6, A7, and Q5.

Specifications

• Product Name: Coolant Expansion Tank Cap / Reservoir Cover
• Part Number: 3B0121321
• OEM / Genuine Part: Yes (Audi / VAG Group)
• Material: High-quality heat-resistant plastic
• Function: Seals coolant reservoir and maintains pressure
• Includes: Cap with internal seal
• Position: Coolant expansion tank / radiator reservoir