VW MK3 Golf, Passat B3/B4 & Vento 1.9L AAZ Crankcase Breather Hose — 028103493Q

OEM engine crankcase breather hose (also known as an intake ventilation or PCV hose) designed specifically for the Volkswagen 1.9L AAZ Turbodiesel engine. This hose connects the cylinder head cover to the air intake system to ventilate blow-by gases — a critical emissions and engine health component.

On 30-year-old AAZ engines, these oil-resistant rubber hoses harden, crack, and split with age. A cracked breather hose causes oil mist to enter the intake, rough idle, excessive crankcase pressure, and increased oil consumption — often misdiagnosed before the hose is inspected.

Part Number

• 028103493Q
• Note: The “Q” suffix designates the AAZ Turbodiesel application — do not confuse with the “S” variant used on other engine codes.

Function

• Connects cylinder head cover to the air intake system
• Ventilates crankcase blow-by gases
• Oil-resistant rubber construction rated for high engine bay temperatures

Fitment

• Volkswagen Golf MK3 (1.9L AAZ TD/TDI): 1992–1999
• Volkswagen Passat B3/B4 (1.9L AAZ): 1990–1997
• Volkswagen Vento (1.9L AAZ): 1992–1998

⚠️ AAZ Turbodiesel engine only (“Q” suffix). Verify your engine code before ordering — other suffix variants are not interchangeable.

Why V DUB HUB

• ✔ OEM Volkswagen — correct factory fitment
• ✔ AAZ-specific “Q” variant — not a generic hose
• ✔ Inspected before listing
• ✔ Factory discontinued — donor sourced