Oil in the air (smog)-pump hose, 420SEL
 

I'm finding droplets of engine oil in the rubber air hose that runs between the engine and the air (smog)-pump.

To be more specific, the engine oil is coming through the "check valve" which is mounted on the timing chain cover. It finds its way to the "stop valve" and then to the "air (smog) pump".

I don't understand how engine oil could be getting into the "check valve". I thought the air pump provided air to the exhaust manifold (upon first start-up of the engine) for "smog control".

I'm not sure if replacing the "check valve" will correct this problem.

I would appreciate any remarks. William