Fruktsallad: I cleaned the inside of the radiator with soda water. filled it up and let it sit, then rinsed it out with distilled water. repeated. hardly any gunk came out.
as soon as the temperatures settle, i'll try turning the fan off completely - should be an interesting experiment
the rad did have a lot of dust in between the fins, i took a vacuum cleaner to it and it's pretty much clear now.
Seal: Yeh that's what i thought - gpu temps contributing to the cpu temps which makes perfect sense. Compounding that problem is my opinion that the gpu gets MUCH hotter than the cpu.
i don't have a temp probe, but after a while the water in the res does get quite warm indeed.
the tubing is 1/2" ID clearflex 60. it's good, high quality tubing but it's just too stiff to work with imo (no idea how i managed to do what i've done).
i think the rad isn't the problem, it's the airflow through the rad. i have the stock bqe 120mm sucking through the rad and it doesn't do a helluva lot
thanks for the encouragement

i'll see this one through to the end dammit.
peteamer: thanks for the suggestion, but space-wise it's so cramped in there that i can't afford to affix it in any orientation other than that i have it in already.
i too was expecting the rad to feel the warmest but most of the time it stays surprisingly cool. the tubing right in front of the rad (cpu->gpu) is also surprisingly cool. i guess i am getting airflow through the rad.
love the story about the girl at the shop

who knows u 2 might get together one day
apocalypse80: the gurgling noises happen when airbubbles enter the res. if i tilt the computer then a few bubbles go from the rad to the res and go *gablurop*. personally, i want to keep this sound as long as possible cos it's just the most awesome sound i've ever heard from my computer.
i just touched everything, and for some reason everything is cool/cold! !? cpu is now idling at 48.
i'll note your tips on radiator cleaning though, seems like good advice. i've asked for help on this before but people usually debate as to which acid is the best to use, without actually talking about how to use it.