I've only done the m62. Are you having an issue with the vanos not clocked correctly m62 only has one per bank but it there was never sooid feedback that I had the vanos set to the "start" position. Not sure what else could repeatedly throw off timing.

With m62 two things I remember was 1: special tool to put in place of the chain tensioner while setting timing. (and turn the engine 720° while doing)

2: after chain tight, snug but not tight the cam bolts and do another 720° to remove any backlash between sprocket and cam.

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)