I had no problems with those parts on my 2001 3.0i with 186k miles at the time when I did the engine work. I actually reused nuts and bolts (and I'm not even sure if I replaced the gaskets) with no problems. California car, so that does make this a little less surprising and maybe relevant.

The fact that you had a failure in the first place suggests you might not find things easy to work on in there.

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2001 X5 3.0i, 203k miles, AT, owned since 2014