I drove mine on Saturday for the first time in two months and had a similar noise but went away after driving a few minutes. My power streering was also kind of funky as I needed both hands to turn the car for the first turns. I guess she doesn't like to hibernate too much.....
It could also be the Vanos Solenoid Valve, having mine replaced, after hearing what sounds like a chain on one of the plastic covers at the front of the engine where the vanos stuff is located.
I'm guessing many vanos issues will have that sound.
Also one of the parts is on back order to Germany, so I'm guessing that I'm not the only M5 to have had this issue with the vanos solenoid valve in the UK.
My sound comes and goes, generally, I'll drive to the shops, say 2 miles, I'll go round the shops get back into the car and this is when I hear it, only at idle or very light throttle, once warm it is fine.Thanks....it doesn't seem to affect power. Is there any potential for damage from driving on the street? On the track?
Sounds like the exact same sound. Like a metal chain rubbing against the black plastic cover, I get it on one side only and if you feel the plastic you can feel it vibrate unlike the other side.Vanos air entraimment has a sound all its own. I bet the tech a cheeseburger it wasn't air when it manifested itself in my 07 because it sounded metallic in nature and caused a vibration in the fore valve cover. (area where the vanos gear set lurks) I lost the bet. There is a bleed-off valve located in the sump near the vanos oil pump which provides for air attenuation in the system......when it's up and running
The selenoid valve a/k/a bleed-off valve is one in the same and is probably the cause of your phantom noise.Sounds like the exact same sound. Like a metal chain rubbing against the black plastic cover, I get it on one side only and if you feel the plastic you can feel it vibrate unlike the other side.
I'm still waiting for the part to arrive to get mine fixed, but they obviously found somethig wrong with it for them to be replacing it.
After your previous posts, I was convinced it was the air, the tech doubted it simply becuase I get my sound at a specific time and he said if it was air I would be geteting it more frequently.
I don't get it at first start up, usually on the second start up if I've left my car for say 20 mins after the initial start-up of the day, which is quite specific.
I could not tell you if air is causing the noise, only that the fault is with the vanos solenoid valve.