Oil Pressure Relief Spring - Type 4 + Waterboxer Engines

This replacement oil pressure relief spring is designed for a wide range of Volkswagen engines, including Type 4 air-cooled engines, the 1600cc CT engine, and petrol Waterboxer engines fitted to Type 25 (T3) Buses. It is suitable for Baywindow Buses with Type 4 engines and Type 25 Buses with both air-cooled and water-cooled petrol engines (not suitable for diesel engines).

The oil pressure relief spring is a critical component of the engine’s lubrication system. It works with the oil pressure relief valve to regulate maximum oil pressure by allowing excess pressure to be released back into the crankcase. If the spring becomes weak, distorted, or broken, oil pressure can become unstable—leading to low oil pressure at idle, excessive pressure at higher RPMs, or premature wear to bearings and seals.

Manufactured as a good quality replacement, this spring is produced to the correct length and tension to restore proper oil pressure regulation. It is a simple but essential part and is strongly recommended for replacement during engine rebuilds or oil system servicing.

Technical Specifications

• Application: Oil pressure relief valve spring

• Dimensions: 15mm x 62mm

• Quality: Good quality replacement

• Quantity: Sold individually

• Quantity Required: 1 per engine

Vehicle & Engine Fitment

VW T2 Baywindow Bus

• 1700cc, 1800cc, 2000cc Type 4 air-cooled engines (1973–1979)

VW Type 25 / T3 Bus

• Air-cooled Type 4 engines

• 1600cc CT petrol engine

• Petrol Waterboxer engines (1.9 & 2.1)

• Not suitable for diesel engines

• Model years: 1979–1992

Key Features

• Maintains correct oil pressure regulation

• Essential for engine longevity and reliability

• Correct size and spring rate

• Suitable for a wide range of VW petrol engines

• Ideal for rebuilds and oil system maintenance

Recommended Associated Parts

• Oil pressure relief piston

• Oil pump

• Engine oil (correct grade)

• Oil filter and oil strainer