Test your skills! Name that part!
 

What's the name of the part between the crossover tube and the oil refill cap? It's a plastic part that goes into the engine. I need to get a new one as mine got broken off when we tried to remove the hose.

There's also a photo showing the hose attached to it.

Next, how do I get the old one out without getting parts of it falling into the engine??

1991 300d, 211k

Crankcase/valve cover breather.

There are two parts actually a soft rubber grommet that inserts into the hole in the valve cover and the second consists of a plastic elbow fitting with an attached plastic tube.

If the grommet still in place is not flexible you might want to order a new one. The elbow/hose combo is 30-40$ and the grommet is a couple dollars.

Just make sure nothing as gone down inside the rocker box ..

item no
 

Would this be the part in question ? mercedes number 617 016 0281
meyle number - MEY 0140010000
See picture.

No, he's showing you a 603, not a 617.

It's called the breather pipe. Most likely 6020100370, but that may vary by model and year.

The grommet is 6010160163

I'm pretty sure mine's a 602 engine, not 603
 

Mine's a 5 cylinder engine so I think that makes it a 602. I think the 603 is the 6 cylinder engine.