Valve cover baffles

[iPee]

I removed the baffles on the intake manifold prior to sandblasting.  I was worried sand may get trapped in the baffles.  One baffle is screwed on the other is riveted.  The bolt on one I was able to put back on, but does anybody know what the purpose of the other baffle is?

The bolt on one is to prevent oil from going into the vacuum lines.  The one that is riveted on seems to just cover a void.  I've been told that it's purpose is to deflect oil back on the cams.  I've also read that it was just to suppress engine noise.  Is it necessary to put the other baffle back on.  I'll be taking the car to the track so not sure if that makes a difference.  I think it would be fine if it was just street driving.

I have no experience use a tap & die set, so I'd prefer not to put the baffle back on, but if I must then so be it.

[cristimm]

Can you post some pictures?

[Delta]

Hmm, youre trying to decide if you need to reinstall the riveted baffle i take it? I cant see any reason that it should be absoultly necessary, although BMW probably had some reason to put it there, whether it be oil deflection or windage prevention or something else.

The baffle that is bolted on must be reinstalled. I cant even imagine the amount of oil that would make its way into the intake otherwise!

[Slowered318]

After pondering this on a number of occasions I came to the conclusion that one side of the valve cover is a vent and the other is a heat shield.

If you have removed the plate it's best to drill and tap 5 or so m3 bolts, install with loctite.