Z3 2.3 engine rattle when engine is cold?

[USz3er]

Has anyone noticed a rattle coming from the engine when the car is cold? It only happens for the first two minutes then it’s gone. It's fine at idle and starts at about 2000 rpm then by 3000 it’s hard to notice. I don't think it sounds like lifters at all. To me it sounds more like the way a ruler sounds when you fling it on a desk and hold it in one spot. Any Ideas? It also does not happen everyday when I start my ride to work and the outside temp has stayed close to the same.

[Quadzilla]

Sounds to me like a little valve lash adjustmet is in order. Also might want to think about a bigger split in the oil like 5/50 from castrol, more flow and higher heat resistance.

[USz3er]

Is valve lash a common problem with BMW's? I really don't think that is the problem. The car runs silent after about 1/8 mile. It also doesn’t loose a drop of oil between changes. Are there any other suggestions? I would think with valve issues I would see a more consistent sound like making noise after sitting for three or four days. But it could be quiet then and make noise the second day. Help

[stjobs]

I personally don't have this problem, but I'll take a shot at it... you say the rattle mostly happens from 2000 to 3000 rpm? Is it accompanied by excessive vibration from the engine? Are you driving top up or down when you hear this? Do you have an aftermarket exhaust? The reason I ask the last question is because certain exhausts have been known to have certain resonant frequencies where they will create a very loud vibration within the cockpit of the car...

stjobs

[USz3er]

It's much easier to here with the top down. No vibration is transferred to me. Everything is stock. I think the RPMs I put are little high I was paying close attention to it and seems more like 1300 to 2200rpm and by the time I'm in second gear there is too much other wind and road noise to hear it. I should also note that even sitting still and raising the Rpms to that rang the noise is then easily heard.