Cooler Master Seidon high temps all of a sudden

Hello all,
I have this system that I've been using in its current config for almost a year now, but recently I've noticed my CPU temps are slowly rising... MOBO is Asus M5A99FX PRO R2.0 (w/ custom VRM cooler), CPU is AMD FX 8350 OC to 4.5GHz (was 5.2GHz but that's now severely overheating), CPU cooler is Cooler Master Seidon 120v (seemed like a good idea two years ago). PSU is Cooler Master V1000 (1KW).

So here's the history of the problem, over the past week or so I've noticed the temps have slowly been rising. First I suspected that the radiator was getting clogged up so I blew it out and a whole crap load of dust came out (my room no longer smells stale while gaming, go figure), that yielded no change in idle temperature and a 1 degree Celsius drop under load. Then I suspected that the cooler may have come loose so I removed it from the CPU, and yes I cleaned it and the CPU off with alcohol and applied new thermal paste. That made no difference.

Before this started, I was able to game for hours on end @5.2GHz at about 48 Celsius. Recently, it has been hitting mid 80's, mid 50's idle, so I brought the OC down, and the temperature problem is still worsening. I'm actually thinking that maybe the coolant within the cooler is starting to break down or maybe there's gunk building up in the waterblock? Either way, it's an AiO cooler, and I'm thinking of replacing it.

Assuming the cooler is the problem (correct me if it isn't), I'm now looking for an AiO liquid cooler that can mount to a 120mm or 140mm fan mount. I would like to go custom, but I have no room for a proper reservoir in this chassis.

Below are images of my setup if that helps

https://drive.google.com/file/d/0B--sybQBf2RnUmZEdGZvSnIxZUU/view?usp=sharing
https://drive.google.com/file/d/0B--sybQBf2RnWFdnN2FUSk9pOXc/view?usp=sharing

Any help is appreciated.

Oh I forgot to mention, my chassis is the NZXT Phantom 530 Black. I have a 200mm fan on the front, a 140mm fan on the bottom front of the side panel and two 120mm fans on the bottom all as intake... As well as two 200mm fans on the top as exhaust and the radiator fan is also exhaust.

I'm going to check BIOS and I'll comment what the voltages being provided by the PSU are.