Sorry for the long post in advance

While enjoying my X on my way home from work, I jumped off the highway and rolled down my windows to enjoy this beautiful weather. When I came to a stop, I heard a squeaking noise and an off putting engine noise. I pulled over and lifted the hood to find that my engine sounded like a diesel. The noise is noticeable on the right front driver side of the truck (squeaking) and the engine sounds like a diesel. Car still drives and runs like normal, no check lights on.

My question is,

1)Will a bad water pump/belt (my thoughts on the squeaking noise) cause my engine to sound like this?

2)Possibly a bad DISA valve causing the noise?

3)Vanos rattle/timing chain guides going out?

The noise corresponds with the RPM's as if something along the belt was the culprit. But would this make my engine sounds like diesel? Oil levels check out at least.

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2002 X5 4.6iS Black on Black
2005 STi WR Blue and BBS Golds

If you want something you've never had, you must be willing to do something you've never done.-Jefferson