Here's a diagram and links to the part nbr index for the parts that alex77ae described in his post above:
BTW, I used my 06 X5 4.4 to pull up the diagram since you have no signature with model/model year/build date info...nor does it appear in the upper right of your posts. No vehicle info makes it more difficult for others to help you better...so really consider adding vehicle info...it helps us to help you better.