H100i high pump RPM and grinding noise when on side.

I've just installed my new H100i (which replaces a faulty H100) and the BIOS is reporting the pump RPM to be around 2900rpm and Corsair LINK V2 reports it as being around 2700/2800rpm. What's causing this and is it something I should be worried about? The pump initially made a high pitched noise. After updating Corsair LINK V2 ver 1.05 and rebooting the computer to double check the BIOS, the noise coming from the pump mostly disappeared.

However, there was still some high pitched noise coming from the pump that I wasn't sure was right. So I tried rebooting with the PC on it's side but the pump started making a loud grinding noise... kind of like a playing card stuck in bicycle spokes are something stuck in a fan. I've checked all of my fans but they're all free from obstruction and the noise is quiet clearly emanating from the pump. Could it be trapped air? I always heard laying the computer on it's side stopped any noise issues related to trapped air/bubbles in the loop.

[EDIT] The original version of this post may have looked like I'd just stuffed a bunch of words up my nose and sneezed but I was acutally holding a conversation as I typed. Sorry that it was less than clear just what the heck I was saying.

First of all, I just need to clarify a few things. When the case is upright and the H100i is in a normal orientation then there's just a high pitched noise that I'm confident in putting down to the pump running at too high of an RPM. After I'd first installed the H100i, the first time I booted up, there was a high pitched whine but that disappeared after I updated to 1.05 and rebooted. After I rebooted, I could still hear a quieter high pitched noise (which sound like the pump is running too fast). As I was not sure whether this was the sound the pump would make when operating correctly, I rebooted with the case on it's side to see if the noise disappeared. My logic being that if the noise did indeed disappear, then it might be bubbles in the system. However, when I rebooted, there was the new and rather loud "playing card in bicycle spokes" noise. This only occurs when the case is on it's side, in the vertical position there's just a quiet(ish) high pitched noise from the pump.

I'm using the 4-pin fans that came with the H100i. When the fans aren't plugged into the H100i, the pump RPM reads as 2275 in the BIOS and the high pitched noise coming from the pump is much quieter (to the point I believe it's normal operating noise) but after about fifteen seconds, it'll jump back up to 2900 or so and the high pitched noise will go back to being excessively loud. The jump in RPM may be down to the fact I hadn't plugged the fans in elsewhere (I only ran the computer for thirty seconds) due to the way I installed the H100i making plugging in the fans to the mobo a big job. I will plug the fans into the mobo and repeat the test as soon as I can to see if I still get the RPM jump. But, before I do that, given the more detailed explanation I've provided of when the clicking noise occurs. Should I still "Try changing the fan's profile in C link and see if the clicking noise changes as well"?

Could the jump in RPM be caused by my mobo uping the CPU_FAN rpm when the cpu begins to get a little bit warm?

I've just tried plugging the 4-pin fans directly into the motherboard but the post screen said that no CPU fan detected. The H100i pump wasn't running. I then rebooted with the fans unplugged and the CPU fan was detected. So, I tried replacing the fans with a pair of Gentle Typhoon's which were plugged into my fan controller but again the post screen said that no CPU fan was detected and again the H100i's pump wasn't running. So I tried to reproduce an earlier result (relevant text quoted below).

When the fans aren't plugged into the H100i, the pump RPM reads as 2275 in the BIOS

With no fans plugged in, I rebooted the computer. The CPU temp read as 25c (and never exceeded 26c) but there was no reading at all for CPU_FAN rpm... If there was a post screen saying that there was no CPU fan detected I must have missed it. Again the pump wasn't running but after I'd been in the BIOS for five or so seconds, it emitted a faint whirr and sprung to life. The whirring noise fluctuated as did the RPM reading which had now appeared in the BIOS. It varied between the high twenty one hundreds to the high twenty three hundreds with a spike up to the twenty nine hundreds.