M40 Top End Engine Noises

[twright]

I have owned 3 M40 powered E30 BMW's. All of them had minor noises coming from the top of the engine.

I would describe these noises as a "clattering". Unfortunately, I know that my American English may not translate very well to British English and this clattering could be called something else.

My current M40 (1993 316i Touring) recently had the head rebuilt and now is very quiet. No more clattering.

Here's what was replaced during the rebuild: timing belt, exhaust valve guides, all lifters, all rocker arms and the cam.

Here's my question:

Which of these worn components was the source of my clattering noise?

[30316]

Most likely worn cam shaft or sticky lifters if the oil service was neglected in the past.

[twright]

In the past, I have discounted the sticky lifters idea, because the noise is different than other cars I have heard with a lifter problem.

The clattering that I have heard doesn't sound the same as lifters because it does not appear to increase and decrease in frequency when I make RPM changes.