Well, first and foremost, make sure that your case, and GPU, are clear of any dust. It's surprising how much dust can affect thermals. On that note, how is the heat for the rest of your components? Have they went up as well, or is it just your GPU?
If clearing the dust does not help (or there is no dust) I would then make sure your fans are in proper working order. No sense in getting rid of what could still be perfectly good fans. (Assuming that, weather aside, your GPU was previously getting decent thermals.) Before switching fans, I would also make sure that you have proper airflow optimization. Make sure all your wires are tucked away nice and neat, and that you're having intake on the "bottom half" (front and side) of the case, and outtake on top half (which would be the back and/or the top.)
If you have your whole rig cleared out, optimized, and nothing appears to be wrong with your case fans or GPU, then I would make the spring for case fans. Arctic Cooling makes some good fans. They are very quiet and move a good amount of air (around 70 CFM, I believe.) They're excellent for their price bracket, and carry at 6-year warranty, I believe. I use them both in my case and on my heatsink. The only issue I have ever had with them is, on my Corsair 300R, I tried putting one as a side-intake, and it made kind of a higher-pitched whine/whir from it sucking air through the small ventilation holes. This was even with using rubber isolators. Pushing air *out* through the top, through the same sized holes, is no issue, however. *shrugs*
Edit: Enermax also makes good fans. Slightly more expensive, and more static pressure, so they are better on a radiator/heatsink. However, they are also slightly louder at full tilt. Either way, you'll pay 1/2 to 1/3 the cost of any Noctua fan, which are widely held in high regard.
Facebook
Twitter
Instagram