The brief
Benny's A4 was leaking engine oil, needing constant top-ups, with a film building up around the top of the engine. He brought it in to have it checked. An oil leak only spreads, the loss adds up, and an engine running low risks low oil pressure and damage, so it wants sorting. The trail pointed at the valve cover gasket. The valve cover sits on top of the cylinder head and seals the top of the engine, keeping the oil in, with a gasket between it and the head. Over years of heat cycling the gasket hardens, shrinks and cracks, so the seal lets go and oil seeps out the edge, runs down onto the exhaust manifold or other hot parts, and burns off. A hardened gasket doesn't reseal itself, and the leak only gets worse, so it needs replacing.
The diagnosis
With the engine cleaned off and run, the leak traced to the valve cover gasket, oil weeping from the seam between the cover and the head, running down from there. The oil filter housing, the sump and the rest of the engine's seals checked out dry, so it was the valve cover gasket. That's a reseal: pull the valve cover, clean both mating faces, and refit it with a new genuine VW-spec gasket, every bolt torqued in sequence to spec.
The work
The intake and the bits in the way came off, the valve cover removed, the cover and the head face cleaned up properly, the cover checked over, and a new genuine VW-spec valve cover gasket fitted, every bolt torqued in sequence to spec so it seats evenly. The oil was topped to level and the engine run and checked warm for any weep. A road test confirmed the cover was dry and the level held.
The outcome
No more oil weep around the engine, the valve cover sealed and dry, and the oil level holding between checks. The A4 went home with the leak sorted at its source. A hardened valve cover gasket only seeps worse and quietly drinks oil, so changing the gasket stopped the leak and kept the engine where it should be on oil.
