On the M62 only the intake or exhaust I think interferes. I would use an inspection camera to check for bent valves, better use a leak down test to measure compression. I'm not sure about N62 though I'd bet they are similar. The added complexity with N62 is the valves change stroke so there's a chance they sometimes interfere

You don't need the guides fixed just get that loose chain on the sprocket and do a rough timing set so you can hand turn the crank.

I helped refurbish a few M62 heads with bent valves, we took about 5 heads apart to get 2-3 working heads; it wasn't that much more work once you are down to chain guides level.

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