Oil in air filter housing

[mb1902.2]

1988 560 SEL - 169K miles.

Does this look like oil inside the air filter housing? It feels a little oily, but I suppose it could be anything. I'm pretty sure that I cleaned the housing when replacing the air filter in May ~ 3K miles ago. I have not seen the oil level drop, but noticed lower oil pressure lately when driving slowly or at a stop light.

Thanks for any advice!

[MTI]

Pressure under the valve cover is vented via tubing to the air cleaner housing. There are "baffles" in the valve cover that are supposed to separate most of the oil particles from the vented gasses.

As the engine ages, valve seals and guides can deteriorate and allow the engine's compression to pressurize the area under the valve covers, increasing the amount of oil that will get past the baffle and into the air filter housing.

[mb1902.2]

Originally Posted by MTI

Pressure under the valve cover is vented via tubing to the air cleaner housing. There are "baffles" in the valve cover that are supposed to separate most of the oil particles from the vented gasses.

As the engine ages, valve seals and guides can deteriorate and allow the engine's compression to pressurize the area under the valve covers, increasing the amount of oil that will get past the baffle and into the air filter housing.

Ok thanks - this makes sense. The car is awsome to drive, and I'd like to keep it for a long time.