new owner looking for assistance

[MrFixIt]

Welcome and congrats on your new X5. We have the same model and year. Mine has 135,000 miles.

Misfires might be caused by loose electrical connections since it ran fine for 500 miles:
1. Check to see if the ground wires between coil #2/3 are properly connected/secured.
2. Check all connections (coils and electrical plugs to coils)
3. What type of plugs are installed, age/mileage?
4. Check fuel injector electrical connections.
5. Check cam wheel position sensor electrical connection.
6. It's doubtful that all four coils one bank 1 went bad at the same time. But to check it, you can switch one with bank 2.

Bank 1 cam position code? Is it P0011?
1. What's the mileage on your X?
2. Might be related to cam position sensor (try switching with Bank 2) or it could be that the timing on Bank 1 is off (chain skipped a tooth?)
3. Are/were there signs and symptoms of failing chain guides, like grinding /crunching noises?

I've just recently replaced all the plastic chain guides as preventive maintenance, they were so brittle and some had already broken off. The X had to no fault codes, but I'm glad I replaced them before the impending catastrophic failure. Now I'm in the process of retiming the cams(had P0011 code)--with a different set of timing tool. Hopefully it will be good to go this time.

Just take a good bright flash light and start your investigation. You have all the maintenance history on the X--very important? I'm wondering what else was done on it besides valve covers. Did they replace the upper timing cover gaskets as well?