I usually posted in my country porsche forum, but nobody know what the noise come from. I posted in this forum because I know there is a lot of boxster experts.

I guess I need to open the oil sump to see what colour is inside, it's ok?

I will try to open the sump an take a photo.

heiwaz,
extanker was refering to opening up your old oil filter (cut the ends off), unfolding the paper element and inspecting to see if there are any metal or plastic particles lodged in the element.
Metal could = IMS bearing wearing.
Black plastic could = IMS bearing plastic shield breaking up.
Red / brown plastic could = chain tensioner guide wear.
If you do find any of the above, the next sensible step is to remove the bottom of the sump to see just how much debris is in there. These results will give you some idea on how to procede next...
Hope this helps - your English is far better than my Spanish too....

thank you very much Steve Tinker, this help me a lot. Now, I've got the IMS bearing cover removed, so I can see the bearing plastic shield and it's in perfect condition. I will open the oil filter to see any plastic or metal particles. Thanks!

Today I remove the oil filter an inspect the paper and I only found in the exterior side this smalls particles of plastic, but is a Soft plastic. The only particle hard is the one of the bottom right, the others are soft.

http://img217.imageshack.us/img217/280/imgp1408.jpg

Looks something like soft gasket material, at least there are no metal specks, but.....
If it was me, the next step would be to remove the sump (oil pan) and inspect the debris laying in the bottom. Not a difficult job +/- 16/18 bolts.

Ok, I will do it tomorrow, but do you know if the sump has got gasket, and if it need to be replaced once is open?. thanks

Your IMS bearing may not look bad from under the cover but the inside seal could have failed allowing oil to wash out the grease in the bearing. Was there any kind of oil leaking from the bearing?

I have removed the IMS bearing to install the LNE, and the old bearing was in good condition.

I've removed the oil sump and the only things I found is the same gasket particles. This particles came from the sump gasket.


http://img405.imageshack.us/img405/4520/imgp1429d.jpg




Otherwise, I discovered that one chain tensioner is harder than the other when you push it. I start a new post whith this issue:

http://986forum.com/forums/showthread.php?t=26941





.

I think, finally find the problem of the buzzing noise.

I removed the spark plugs, and found in the spark tube (1) ans stranger particle non metallic, I hit with a hammer and it broke in 3 pieces. I believe is a little stone and it done a vibration doing the noise. Do you think is it possible?
In this spark tube had an oil leak inside, too.

http://img148.imageshack.us/img148/9752/imgp1436a.jpg