This is what I would do in this situation:
1. Read fault codes and investigate based on their description.
2. If codes inconclusive proceed with the following steps
3. Carefully inspect all components that you touched during repair work – vacuum hoses, idle control valve, electrical connectors, throttle body, DISA valve, etc. Make sure all seated correctly.
4. Remove spark plugs for inspection – large piece of gunk could easily foil new plug after the first start – clean with break clean and dry it out using propane torch.
5. Re-check compression – hopefully you’ll get more uniform readings
6. Assuming compression readings better (uniform) then previous test – re-install spark plugs and take car for a good test drive. It might take time to clear all of the oil from intake and exhaust.
7. Good luck!

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2012 X5 x35i My new toy
2005 X5 4.4 Her's (Retrofitted Servotronic Steering Rack)
2003 X5 3.0 Mine (Retrofitted Servotronic Steering Rack and Heated Steering Wheel)
2001 M5 Son's car
2000 540i 6sp Sports pkg, supercharged. Son's car (Sold)
2001 530i (Sold)
1999 528i (Sold)
1975 2002 (Sold)