You didn't ask this question, but you can use any M54 3.0 (M54B30) engine from 3, 5, Z3, Z4, X3, or X5. The early engines ('01 and early '02) had a different coil pack, valve cover design, and wiring, so if you use a later, post '02 or so, you may have to keep your orig valve cover, and coils.

you will also need to use an X5 oil pan, which is okay, because you will want to change oil pan gasket (and a several other things) anyway

check out car-part.com for good used engines. Some with warranties. Read & follow the fine print of the warranties if you ever hope to collect on one.

I have one used and 3 rebuilt/freshened M54B30's. The latter have new, updated piston rings, new water pipes, and all new gaskets, so they should not consume any oil. If you are interested in one and want to come to the Boston area, send me a PM..