Noise at idle

[pquast1]

I'm sorry if this has been a topic before, I couldn't find it. How do you know if the VANOS is starting to fail or need to be replaced? When sitting in gear at a light or stop sign I can hear a rattle noise coming from the engine compartment. When it began it did it when the motor was cold and once it warmed up it went away. Now it does it most of the time.

2005 E53 3.0l 127k miles

[ArmyX5]

I had the same noise and it turns out to be the belt tensioners. There are two of them, one for the compressor and one on the main belt. You can test all the pulleys, one at a time, by applying a small amount of lubricating oil to them. Apply the lubricating oil one at a time and start the engine and see if the noise goes away or decreases. I have the same X with the same amount of mileage and if you have not replaced both tensioner pulleys, them that is for sure your problem.

[srmmmm]

I haven't had to touch my VANOS, but I have stuck with the Castrol synthetic and change oil every 8,000 miles (which is every 3 months for me).

2002 X5 3.0 259,780 miles
2004 325i 115,000 miles (no VANOS issues on the CEO's ride either)