***update****

I took my x5 to an Indy shop today and this is what I've been told thus far:

He said I have a bad vanos. I can't quote him word for word and I may screw up some of the details be here's what I gathered, he was saying:

- that the bad vanos was preventing the valves from closing, they were stuck open.
- the injectors were giving fuel and there was spark.
- he would need to change the vanos
- 9.5 hours of labor
- currently at at least $800 for labor but still tallying it up and this cost doesn't include the cost of the parts.

does this sound like an accurate diagnoses? Does the current cost seems reasonable?
I'm comfortable with working on cars, so is this something a shade tree mechanic like myself can do?

I tried finding a DIY on vanos replacement but I haven't been successful yet.

I don't even know what the vanos looks like or where to find it on the engine.

__________________
2000 X5 4.4i w/ 150K miles.