I noticed on my BX23 I have had the same noises. One coming from the back hoe and one comes from up front somewhere. The one in the back is constant, but the one up front comes and goes. It seems to be on the front left hydrolic assembly for the FEL. I seem to notice it more at higher RPMS.
I have detected no leaks and all seems to work fine. I have notice the right hydrolic assembly on the FEL seems to activate sooner than the left when lifting. But assume its normal as there is visual no damge to the lines or welds on either side of the FEL.
At least I hope thats the case as I can only assume, which to me means ASK-U-ME. So I am also asking if this normal, which I should have done before I assumed.