M44 Oil Check Valve in Block
 

Referring to #9 and #10 in this link: http://www.realoem.com/bmw/enUS/show...diagId=11_6099

The check valve is lowermost, then there's the rubber spacer sleeve above it. I'm wondering how high above the surface of the block the spacer should protrude? Should it be making contact with the head gasket? And should it be replaced? My spacer is sitting flush with the block, see the picture below.

It should be flush with the block.
Knowing that rubber material gets very hard and brittle when exposed to oil and heat after so many miles, I would replace the spacer.
Make sure the non-return valve is oriented correctly.
Although not sure if the check valve can be installed backwards though, just making sure.
It prevents oil from draining back to the pump and oil pan.

Believe it or not, the spacer is still quite pliable. I did learn that the M42 engine omitted this part, although some have modified their blocks to accept it. Based on that, I'm going to leave it as is.

Good call. I would also put it back.

It's just a flow restrictor that limits oil flow to the head so the bottom end still gets oiled sufficiently and also an anti-drain back to keep the oil passages in the head, cams and lifters filled up. Prevents lifter tick at start up.

I'm cleaning my head now on my '97 M44 and my Haynes manual is not too clear on how this comes out. I want to replace it with a new one as a proactive measure. Is the rubber spacer just holding it in place or does this need to be threaded in from the bottom end of the block?

Bentley book doesn't mention it either, not surprising. Judging from images, I'd say the part slip fits into a shouldered hole, and the spacer holds it in. A pick should remove the spacer, same pick or a magnet for the check valve. Those are pricey little parts:

https://www.google.com/search?q=1111...T8cBvjK-ZPJYM:

https://www.google.com/search?ei=z54...iz.3Oe_TCt_va0

Here's someone else's account: http://www.318ti.org/forum/showthread.php?t=33112

South Bend, eh? I've got a lathe that was made there, almost 59 years ago.

My grandfather may very well have built part of that lathe LOL! Very cool. Thanks for the links and info!

If you do replace it, let us know how it goes.

As stated earlier, the grommet is just a rubber sleeve and mine popped right out with a bit of urging with a pick between the grommet and the head. The check valve pulled right out with a pair of needle nose pliers and the new one dropped right in place after I cleaned out the oil feed chanel and the little machined step the valve sits on. Pushed the grommet back in easy as pie. The grommet sits just proud of the head surface and seals between the valve and the gasket.

Success! Thanks for posting the outcome, hopefully, someone else will benefit down the road.

So your grandfather worked at South Bend Lathe for a long time?