Not sure if you fixed this issue, but I have the h100i and my temps are no where near that bad, I do remember that I found that the mounting bracket for the h100i wouldn't fit snug to my z370p motherboard after researching this I found out that a lot of the z370 chipset mobos are a little thinner than what the h100i was made for, no big deal if you have four extra washers that came with it like mine did, you can use those so that the mounting posts will be snug to the mounting bracket which will remove any wiggle room. Also, I don't believe in using preapplied thermal paste so I actually removed the old thermal paste (snarkily looking at you the verge) and applied a small amount of higher quality paste to the cpu using the classic pea dot method.
Hope this helped