http://forums.e60.net/index.php?showtopic=46764
First of all, this has not happened to me (knocking the wood however). And this concerns DIESEL engines.
I've been reading one Finnish BMW forum and some people have reported a major engine malfunction caused by the broken intake manifold.
To be exact, swirl flaps inside the intake manifold have came loose and were sucked into the cylinders --> major malfunction obviously.
This problem has mostly happened to e39's with 3.0l diesel engine. Ok, not to worry I thought until it brought out that there has been already some e60's too.
Inside the intake manifold, there are six swirl flaps, which open when throttle is opened. What are they for? Probably because of emissions when the engine is idling. Swirl flaps have came loose because of slag in the manifold. There has been so much slag that flaps have jammed. And because of mechanism trying to move them, their axels have broken. The intake manifold gets very dirty because of recycling of exhaust fumes.
Here is a pic of those swirl flaps inside the intake manifold. And this is from e39, but it looks almost exactly same in e60. (This picture has been taken by a user named "dieselrules" and it's from a Finnish BMW forum, but I think he doesn't mind I'm using it here.)
You can see the axels of swirl flaps inside. In this picture the flaps are open. But as you can see, there's lot of s*it inside.
Some people have cleaned their intake manifolds. However, many e39 owners have removed these flaps completely and reported that there's no effect to anything in car. Their cars have passed vehicle inspections normally, no differences in emission measurings. Sure these flaps have a meaning, but...
BMW itself has not taken any stance on this. Of course these e60's has been older e60's (2003-2004) with some 100.000 kms in them. Someone mentioned, that BMW has improved the structure of these swirl flaps from 2005 along the M57N2 engine, but I'm not sure...
I have a 530d 2004 with 83.000 kilometers, so I got a bit worried about this and took out my intake manifold just to check it out. Sure there were slag in it. But not so much that the flaps could get broken, yet. Just now I'm kind of waiting for some official aspect from BMW to get on with this thing. A new intake manifold you may say... Sure, but if I can manage this issue a bit cheaper, for example cleaning my intake manifold completely, I would do that.
Have you run into this kind of problem anywhere? What do you think? Maybe an old issue?
Acho que já tinha lido por aqui algures a falar sobre estas "palhetas" (ou outra coisa qq que queiram chamar a isto)
Os modelos mais recentes já não tem isto na admissão?
Apesar de ter garantia de 1 ano da BM não me tá a apetecer ficar sem motor por uma coisa tão ridícula como partir-se uma destas "palhetas" e ser engolida por um cilindro.
Ops!!! Sei que havia problemas das palhetas com os E46 150cv agora com os E39 530d ainda não tinha visto em nenhum lugar... acabei de trocar a minha 320d 150cv por uma 530d pensando que teria eliminado esse tipo de problema, agora ja começo a ponderar tambem a eliminição dessas borboletas..... Se alguem souber de mais situações desse tipo com os E39 530d que deixe aqui o seu contributo, para uma futura precaução ao problema.
Vc não entendeu direito.... Não estou a rir de nada simplesmete fiquei com a esperança da sua possivel informação sobre a questão dos 530d que vc comentou em tentar saber na bmw..... quem não percebeu a sua agressividade fui eu pois não ando por aqui a gozar com os problemas dos outros pelo contrario ajudo sempre no que posso... 
