T25,G1,G2 Oil Filter Housing To Crankcase Gasket

This oil filter housing gasket seals the joint between the engine block and the oil filter housing (the cast adaptor that the spin-on filter screws onto). It’s a small gasket, but it does a big job: it keeps the engine’s pressurised oil system leak-free where oil is routed from the pump through the filter housing and back into the main oil galleries.

Over time, heat cycles and oil contamination can harden and flatten the gasket. Once that sealing face degrades you’ll often see an oil weep or drip around the filter housing, oil tracking down the side of the block, or a persistent “mystery leak” that looks like the sump gasket or crank seal at first glance. Replacing the gasket restores a proper seal and helps keep oil pressure stable (and your engine bay/driveway clean).

What the part does and how it works

Inside the housing are oil passages that carry oil under pressure. The gasket sits between the housing and the block and seals multiple oil ports at once. When the housing bolts are tightened, the gasket compresses to fill tiny machining marks and prevent oil escaping under pressure—especially when cold oil pressure is at its highest on start-up.

When you should replace it

• Oil leaking from around the oil filter housing / block joint

• Oil pooling on the gearbox bellhousing or running down the front of the engine

• Housing removed for other work (ideal “while you’re there” item)

Fitting notes

• Oil filter housing to block gasket

• Clean both mating faces carefully (no old gasket material, no gouges).

• Lightly oil the gasket before assembly (unless your workshop manual specifies otherwise).

• Torque the housing evenly so the gasket compresses uniformly.

Other parts you may need (depending on engine / what you’re servicing)

• Oil filter (worth renewing while you’re there)

• Fresh engine oil (you’ll usually lose oil when removing the housing)

• Oil cooler seals / O-rings (if your engine uses a cooler mounted to the housing)

• Housing bolts / washers (only if yours are damaged/corroded)

• Degreaser/brake cleaner to prep the sealing faces

Compatibility overview

Engine fitments noted:

• T25 diesel: CS, JX, KY

• Volkswagen Corrado: up to chassis >>50-M-027 000 (KR, PG, 9A, 2E, ADY)

• Mk1 Golf: 1.6–1.8 (EG, EM, EN, FR, GH, JB, CR, etc.)

• Mk2 Golf: up to chassis >>1G-MW720 000 (SB, RA, MF, JR, 1V, ME, PG, ABN, 9A, RV, RP, PF, PB, RH, RF, PN, GU, PL, KR, EZ, etc.)

• Also listed for: Golf Mk1 Cabriolet, Volkswagen Caddy Mk1, Volkswagen Scirocco