Anyone want to explain VANOS?

[Kaan]

On the road right now, but theres single vanos and dual vanos. And its very different than hondar VTEC. Its based on advance, not on "dual cam profiles". Your car has single vanos (on one cam, the intake), S54s had dual vanos (both cams). If I get some time tonight when I get to VIR ill write out what it does, but it simply adjusts the cam timing based on load (a combination of throttle position, revs, gear).

Why you need to rebuild it is mostly the seals (bmw rubber/plastic goes brittle), or you can get a build for it to make the gears more "efficient" (less drag), but thats almost useless.

ok this makes more sense now. honda must have stolen this idea because the "new" i-vtec also does the vanos timing thing as well as the old change the lobes...

If your vanos is broken, it probably just makes the car feel slow. if its "leaky" you just arent getting all the timing.

DJ do you know if the computer is reading this and not throwing in the ignition timing advance due to pressure loss? i'm assuming something is keeping the ignition timing down because if it wasnt, there would be a lot of bmw kids crying about how vtec broke their shit.