I bought a used x5 300+ miles on it. takes a bit to get it going, when it does finally start it stalls after a few seconds. I've also noticed Small amount of oil in air box and coolant leak which I think is coming from I take. It will idle longer when engine is warm. Idle speed seems fine.

Check your sparkplug. What it looks like might give you an idea if have a fuel problem. Hard starting is sometimes a sign of valves needing to be adjusted.