GTX 970 - 80c on full load?

Solution
Temps depend on ambient temp, case, dust buildup, etc. 80C is still well within safe temps (max 98C).
http://www.geforce.com/hardware/desktop-gpus/geforce-gtx-970/specifications
You could also change the fan profile and set it to a more aggressive fan curve to help keep temps down with a program like MSI Afterburner.
https://gaming.msi.com/features/afterburner
Another thing that will help, at least a few degrees C, is replacing the thermal paste on the GPU. I've used MX-4 and it brought down my temps around 4C on both GPU's.
https://www.arctic.ac/us_en/mx-4.html
Temps depend on ambient temp, case, dust buildup, etc. 80C is still well within safe temps (max 98C).
http://www.geforce.com/hardware/desktop-gpus/geforce-gtx-970/specifications
You could also change the fan profile and set it to a more aggressive fan curve to help keep temps down with a program like MSI Afterburner.
https://gaming.msi.com/features/afterburner
Another thing that will help, at least a few degrees C, is replacing the thermal paste on the GPU. I've used MX-4 and it brought down my temps around 4C on both GPU's.
https://www.arctic.ac/us_en/mx-4.html
 
Solution
1st thing, clean it. Blow out any dust.
2nd is set the fan speed at 100% using something like Afterburner.
If the fan isn't spinning despite throttling it, turn it with your finger. If it doesn't spin, time to replace it. If it spins, I would still replace it since it's on its way out. Search for replacement fans. They're out there. Probably Ebay.

If it spins and still super hot, check your computer for malware. I know some malware can sometimes peg cpus. It might be possible for gpus to be affected the same way.

To be sure, buy an aftermarket solution.
http://www.amazon.com/ARCTIC-Accelero-Mono-Graphics-Cooler/dp/B006DAD8HS/ref=sr_1_5?ie=UTF8&qid=1472565288&sr=8-5&keywords=gtx+970+cooler