The rattle is coming from gears behind vanos and depends on a spring that have lost elasticity over time. Spring decide how much oilpressure. Softer spring = low pressure and to much clearance between gears = rattle. to compensate for soft spring one can adjust oilpressure upp to normal level. Or one can buy a new vanos, I dont think one can buy just oiloressure regulator. This is not my idea I just fel that everyone that have a s50 can enjoy a silent vanos,according to swedish Autopower the tip come from Germany to Autopower. http://www.autopower.se/forum/topic.asp?id=241942
Here is a translation of one reply.
Believe it is because there currently is vacation time. It had certainly been more pull in this thread otherwise.
The solution to the vanos rattle has been with the mechanics of the BMW workshops in Germany for at least 15 years (according to member of German forum) but has apparently had a duty of confidentiality or the like thereof. And here in Sweden "has no idea" about this when I asked.
I got a tip via pm to try this by starting a thread in a German forum about my problem. Where it was apparently quite well known method among member why.
One can in retrospect to wonder how many vanosenheter who replaced unnecessarily. The fact that many engines have been replaced due vanosras, well. Read the bottom bracket race instead. Vanosras is a concept that apparently only exists here in Sweden, unfortunately.
To send the device to Dr. Vano is reportedly 200-300 mil then rattle back (pressure). Changing the oil viscosity / oil the 100th mil then will rattle (print again).
Rattle is well known that the pressure in the unit has become too low over time and mekaninken loose in it, hence the rattle.
What I am looking for full right now is what the pressure will be on the vanosenheten so it is possible to measure and obtain a more precise adjustment of pressure.
And for those of you who have not tried, like bums with a 19mm wrench and 6mm Allen key and adjust the engine is warm. It works! We S50 owners should not have to be ashamed of rattling vanos!