M50 Cylinder Head Non Return Valve

[93 525 Paul]

It's the check valve in the cylinder head, I had in my mind that there were threads expounding the need to replace it. Tried a number of searches to no avail. banghead Is there a way to test it or is it just a "if you have the head off, replace it" deal?
Number 2 "non return valve" in this diagram, part number 11121735180
http://www.realoem.com/bmw/diagrams/d/h/1.png
I want to mate the head to my block but was wondering about this thing. Simple check valve device should be easily tested. Does it nee to hold 3 bar or???

[whiskychaser]

Dont think it needs to hold 3 bar - I think the idea is it just stops oil from draining back down? IIRC they unscrew if you want to replace them. I just made sure mine wasnt stuck

[93 525 Paul]

Dont think it needs to hold 3 bar - I think the idea is it just stops oil from draining back down? IIRC they unscrew if you want to replace them. I just made sure mine wasnt stuck

Mine seems fine, clean as a whistle and works, can see the ball and spring check valve. Holds a bit, it's a very light spring.
Thanks! No excuses, mount that sucker up...

[93 525 Paul]

Here's what it looks like, came out easily back when I was cleaning the head up, lapping valves etc.
http://i123.photobucket.com/albums/o284/pmcdougal/headcheckvalve2-1.jpg

Here it's being reinstalled in the head
http://i123.photobucket.com/albums/o284/pmcdougal/headcheckvalve1-1.jpg