Whats this and how should it look?

Can someone please help me out here, Iv acuired a series 3 that has had the oil trap air filter removed and replaced with a K&N lol i know......

Heres a picture of the bottom of the engine where the timing cover is and to me it looks like a oil breather that is missing something, also when i rev the engine oil does slightly spit out the hole.

Can someone tell me what is missing please it doesnt mension it in the Haynes manual.

another blinding intro! noobs are on form today

Its a Series III Deisel 2-1/4 N/A,

You should be able to see a coarse mesh in there. Not a breather as such more to let the timing case drain. The plug should be located in the hole on the left hand side but it's missing.
Oil shouldn't be coming out of there so the front crank or camshaft seal is gone.

Edit. Just read it again ...I was talking about a 2,5 ... Is the timing case of the 2.25 filled with oil for the chain?