A method for combusting a vapor of a fuel accumulated in a crankcase of an engine, the engine disposed in a vehicle having a fuel tank and an adsorbent canister coupled to the fuel tank. The method comprises flowing compressed air from a first air source through the crankcase to yield a crankcase effluent enriched in gasses leaked from the combustion chamber, which include the fuel vapor. The method further comprises combining the crankcase effluent with an effluent from the adsorbent canister, also enriched in the vapor, and, flowing the combined crankcase and adsorbent-canister effluent to an intake of the engine via a conduit.