Need diagnosing service via internet.

[lexkaz]

I have teamviewer + laptop + ista/inpa + bmw X6 e71 n63 connected
paypal account to make you payment

need to diagnose misfire on cyl 5

coil / plug / injector all replaced and changed no result.
engine completely rebuild

[jclausen]

At this point I would recommend a visit to a good independent bmw shop

[elthox]

It appears that mechanically you have done almost everything.
If Ecu reflash seems the last option i can help with that

[328 Power 04]

A reflash is probably not going to fix things on one cylinder...

A confirmed compression test plus leakdown test would be important, and then maybe checking the DME hardware or simply cloning into another if an electrical fault happened. For example, if the ground for the ignition coils wasn't installed correctly and the engine was ran, you may have damaged the dme. I can make you a spare virgin dme if needed, but I suggest testing mechanical things if not already done.