My 2009 Justa with 107,xxx miles makes a whirring noise with RPMs. It is coming from the middle of the oil pan, not the belt or accessories. You can feel the noise if you put your hand on the oil pan. At low rpms it is like a buzzing. Turns to a whirring at higher rpms. No CEL codes or other problems. Mechanic says oil pressure is good.

Just had the water pump and belt tensioner replaced and it did not change the noise described above.

I plan to take off the oil pan and look at the oil pump. Has anyone else trouble-shot this problem and have any tips on what to look for behind the oil pan?

Thanks in advance.