SUPERTECH inlet valve stem seals VAG 1.8T 20V

Audi, Volkswagen and Seat engines concerned

These seals fit the 6 mm stem inlet valves of the VAG 20-valve 1.8 turbo four-cylinder, fitted among others to the Audi A3, S3, A4 and TT, the Volkswagen Golf 4, New Beetle and Polo GTI, and the Seat Ibiza and Leon.

This engine has five valves per cylinder, three inlet and two exhaust, giving 12 inlet valves per cylinder head. The original seal caps the guide and wipes oil along the stem; the VW Audi Seat Skoda factory catalogue lists it as 036 109 675 A, with 20 seals per engine, inlet and exhaust combined.

SUPERTECH inlet valve stem seals

The stem seal lets through just enough oil to lubricate the valve stem in its guide, and no more: without that oil, the stem and guide wear. Once worn or hardened by heat, the seal lets oil run down into the combustion chamber: oil consumption, blue smoke on start-up or after a long idle, deposits on the valves and spark plugs.

SUPERTECH inlet seals are moulded from a high quality rubber compound, a polyacrylate (ACM), and fit an 8.8 mm outside diameter guide for a 6 mm stem. The set of 12 covers every inlet valve of one cylinder head; the hotter exhaust side takes seals in a dedicated high-temperature compound, sold separately.

Stem seal technical specifications

Stem seal installation

Technical guide

The brand offered

SUPERTECH, based in San Jose, California, manufactures valvetrain parts for built engines, from valves to springs, guides and stem seals. Its range covers European, Japanese and American engines, from road use to racing.

Inlet or exhaust?

Both seals have the same dimensions but not the same material: the inlet takes the VS-VBM6-I polyacrylate (ACM) seal, the exhaust the VS-VBM6-E Viton (FKM) seal, designed for the higher temperature of the exhaust valves. Polyacrylate withstands up to 177 °C (350 °F); Viton, 204 °C (400 °F) continuous according to SUPERTECH. The 1.8T 20V needs 12 inlet seals and 8 exhaust seals.

When valve stem seals must be replaced

• Oil consumption, blue smoke on start-up or after a long idle
• Valve removal or cylinder head rebuild
• Valve guide replacement
• Fitting reinforced valves or springs

Vehicle compatibility

Audi

Volkswagen

Seat

OEM part number (VAG stem seal): 036 109 675 A (replaces 036 109 675)

Remember the exhaust valve stem seals

Inlet valve stem seals are replaced together with the exhaust valve stem seals. We offer the SUPERTECH seals for these engines: