This is a PSA to N63 owners about a noise that can be hard to catch on the N63, and could be detrimental to your engine. As if the N63 didn’t have enough issues already!
I have seen this issue only a handful of times, but only on the N63 not the TU versions. The noise can show up differently as well. I have had it only at idle when there is a whining noise that sounds like its coming from the passenger side dash. Also, had a loud whining noise when at 1200 to 2500 rpm. To isolate the noise, you can hear it best on the engine oil cooler lines using a stethoscope.
As mentioned before, I have only seen a handful of these pumps come in making a noise. After reading the forums I have found many other N63 owners are having the same issue. The oil pump is a very important part of the engine and is worrisome if it is making noise for engine health. If the oil pump fails, the pump will not supply oil to the motor important moving components and will cause major damage and eventually engine failure.
The pump is easy to replace, which is surprising since most things on the N63 are not easy. You just remove the lower oil pan and can access the pump. Remove the 3 bolts securing the pump sprocket. Release the bolts holding the pump and remove the pump. Replace the pump seals and reinstall in reverse. Check the oil pump chain tension. Do clean the threaded holes for the lower oil pan using a tap. These are not exact instructions just representation on how easy the repair is. You should always check repair instructions before doing the repair.