Smart 450 / 452 partial load valve for SMART Fortwo Coupe Roadster 1998-2007 599ccm and 698ccm

Fitting: SMART Coupe/Fortwo/Roadster 599ccm and 698ccm engines

As many people know, the Smart's original valve isn't really any good. The pressure in the engine and oil vapors cause the valve to quickly fail. This causes the engine to push more and more oil into the intake tract. This oil migrates into the combustion chamber where it is burned. The result is an increased combustion temperature. Eventually, parts of the exhaust valves burn off and the cylinder loses compression, meaning the Smarti only runs on 2 cylinders. The excessive combustion temperature also causes oil sludge to settle on the pistons and piston rings. The piston rings then no longer seal properly... even more oil gets into the combustion chamber.... the rest you can imagine.

A notice: Some colleagues sell check valves with rubber valves/plates inside. These rubber parts begin to dissolve when they come into contact with oil, see photos. Everyone has to know what they are installing. I advise against it. After a short time, the rubber part becomes porous and the valve function deteriorates. Such a part was installed in my old Smart. This part no longer had a function. => So valve fire, seized piston rings => Engine overhaul...

Scope of delivery:

• 1 piece check valve
• 2x matching hoses (resistant to oil and fuels)
• 4x matching hose clamps

Method: Simply cut the plastic pipe at the marked location using a cutter/knife etc. Cut it off and install the new ventilation unit there with the enclosed clamps. See pictures.

Important: Make sure that the arrow on the check valve points in the direction of the intake bridge.

Advantage: With this approach it is not necessary to lower the engine or open the rear part of the vent near the air conditioning or remove the water pump. Unless this is also already porous and cracked. We also offer suitable hose pieces for the rear part.