Oil Vapour Recovery System on a Renault Clio 1.8 16V

In this video, we see how naturally aspirated engines (without a turbocharger) tend to emit oil vapours from the sump, which end up in the intake, contaminating throttle bodies, valves, and increasing consumption. The solution is to install a vapour separator (also known as a "catch can") to filter the oil vapours before they enter the intake; this eliminates carbon deposits in the engine and extends the lifespan of the injectors and valves.

You will need a recovery tank (the catch can): you can find it, for example, at race-shop. It has code 258.890 at a price of £34.30 (shipping costs not specified); 10 mm heat-resistant metal tubing, AN010 fittings, and M16X1.5 threaded adapters for the valve cover; optional breather filter to avoid pressure in the tank.

Disconnect the original rubber hoses from the valve cover and replace them with an M16 threaded fitting, connect the metal tube to the valve cover and the catch can, positioning the tank away from heat. You can choose between two configurations: the first without a return to the intake, where the vapours condense in the tank and do not return to the engine (must be emptied manually), and the second with a return to the intake, where the purified air returns to the manifold (closed system, but less effective).

In any case, you will achieve less contamination in the engine, optimal pressure in the sump, and all with maintenance performed every 5,000 to 10,000 miles. Use heat-resistant hoses, and ensure the catch can is airtight.