G3 Rocker Cover Breather Valve - 1.9 Diesel

This rocker cover breather valve (also known as a crankcase pressure relief valve) is fitted to the top of the rocker cover on a wide range of VW 1.9 diesel and TDI engines. Its role is to regulate crankcase pressure by allowing excess blow-by gases to escape safely into the breather system, preventing pressure build-up inside the engine.

As diesel engines age, these valves can become blocked with oil sludge or carbon deposits, leading to excessive crankcase pressure. This can cause oil leaks from seals and gaskets, increased oil consumption, or oil being forced into the intake system. Replacing the breather valve restores correct pressure control, helping to keep the engine clean, leak-free, and running efficiently.

This is a direct replacement reproduction part, designed to locate securely into the rocker cover and connect to the factory breather hoses without modification. It is suitable for both naturally aspirated diesel, turbo diesel, and TDI engines, where fitted with the engine codes listed below.

Function & Benefits

• Controls and relieves crankcase pressure

• Prevents oil leaks and gasket failure

• Reduces oil vapour contamination in the intake

• Helps maintain correct engine breathing and performance

• Direct-fit replacement for original valve

Quantity & Fitting

• Quantity: Sold individually

• Location: Push-fit into the top of the rocker cover

• Fitting Tip: Always check breather hoses for blockages or hardening when replacing

Engine Compatibility (Watercooled Diesel)

1.9 Diesel / Turbo Diesel / TDI Engine Codes

• 1Y – 1.9 D

• AAZ – 1.9 TD

• AEY – 1.9 SDI

• 1Z – 1.9 TDI

• AFN – 1.9 TDI

• AHU – 1.9 TDI

• ALE – 1.9 TDI

• AVG – 1.9 TDI

Vehicle Fitment Summary

Volkswagen Caddy II

• 1995–2004

• 1.7 & 1.9 Diesel engines (64–90 bhp)

Volkswagen Golf Mk3

• Hatchback & Cabriolet

• 1.9 Diesel / TDI engines (64–110 bhp)

Volkswagen Passat B3/B4

• Saloon & Estate

• 1.9 Diesel / TDI engines (68–110 bhp)

Volkswagen Passat B5

• Saloon & Estate

• 1.9 Diesel / TDI engines (90–110 bhp)

Volkswagen Polo Classic

• 1.7 & 1.9 Diesel engines (57–110 bhp)

Volkswagen Sharan Mk1

• 1.9 TDI engines (90–110 bhp)

Volkswagen Vento

• 1.9 Diesel / TDI engines (64–110 bhp)