so I've recently put together a new computer and opted for the CM Nepton 240M cooler for the i7 6800k processor. I have it installed and connected on an Asus Sabertooth X99 mainboard, using the supplied Y-splitter for the two fans and a separate mainboard connector for the pump.
Thing is, soon as I turned it on, the pump's been making a lot of noise which frankly sounds like water gurgling through an old radiator. It's like a constant, non-stop 'wheezing' sound. I've had it run many hours on several days by now so it's not something that just 'settles in'.
I've also tried other suggestions I've found online, such a turning the case around while it was running. When I put the case flat on its back (with the pump facing upward) I heard it 'spin up' noticeably, with the wheezing disappearing for a moment but then it returned. I then (PC switched off) put it on the other side, so the pump was essentially facing downward and now there was no wheezing sound at all when I booted up, just a light occasional gurgle. I let that run for a few moments and then put the case upright again, how it's meant to be and the sound returned pretty much immediately.
Just to check, I rebooted my PC once with the pump unplugged from power and the noise wasn't there, so I can pretty much rule out other components.
Does anyone have any suggestions what else could be done or checked here? I'm just wondering if I'm doing something wrong or fundamentally misunderstood something here. I can't imagine that constant scratchy, wheezy is normal or that the installation requires some secret trick to make it work as it should.
Any help would be appreciated,