I'm not sure the total time. I spread out the tear down over a few days. Then ordered the parts. While waiting I cleaned / painted stuff and prepared for install. Also did the Vanos seals while waiting. That is half a day probably. Once I had the parts, it took me about a day and a half of assembly before I could start it.

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2001 X5 4.4i Sport
2013 550i Xdrive M Sport
2000 528i E39 (Sold)
Unleashed Air Racing 279 mph Best Average Speed