I know there is a separate topic on oil separators, but thought I do a DIY on this.
Related thread:
Oil Separators - Loud Whistling Noise @ Idle
Thanks to
@Teddis for suggesting I do this replacement! It was well worth it, as you will see.
This job takes a total of 20 to 30 minutes.
Starting with the parts you would need (P/Ns are in the labels below). You need a right and left check valves (non-return valves), each of them with two o-rings (a black and green o-ring per each valve).
I also purchased the hose, in case I needed it, but the one in my car was fine so I ended up leaving the old one. This one is being returned. The job would be extended about 1 hour if you install this hose, as you need to take out the undercarriage cover.
Start by removing the engine cover. You’ll immediately see the check valves. To remove the connections, just press on the round plastic (you’ll see where you would need to press), and pull. This is connected with an o-ring, so it would slide out. There are two connections per check valve.
To remove the check valve body, you’ll need an E10 socket. Remove the single screw as much as you can and start pulling up the check valve once the screw clears the threads.
Pull the check valve up.
This is the piece where the check valve mounts. You can see both o-rings. The green o-ring goes on top, black on bottom.
Remove o-rings, preferably with a hooked pick, and clean the area.
New o-rings in place…
You can see the old check valve on bottom of next photo. New check valve on top.
Reassemble everything back. Connect the two hose parts first (you’ll hear a click), then connect the check valve to the engine valve cover by pushing valve carefully over the o-rings.
Tighten screw.
Applied torque to the screws = 9N-m.
If you need to replace the rest of the hose, there is only one additional connection that you must undo to take the hose out. That connection is on the bottom, on the right side of the car. I think this hose connects to the main hose of one of the turbines (but not sure). Just take the undercarriage cover out, and the right side spoiler cover and you’re see that connection there. It is the same type of connection as above.
Since the hose was OK, I didn’t want to mess up with this connection and risking breaking something else.