As a test, yes. Setting your refresh to 60hz and turning on v-sync as an experiment can't hurt and it would let you know if the card is being over stressed. Could be VRM temperature getting too high and causing instability.
You can try re-seating the graphics card. You would be surprised how often that works. After a few hundred temperature cycles the cards can wiggle themselves out of contact with a pin or two. Just the act of unplugging it and putting it back in can help.
And of course the PSU, if dirty power is getting to the card and it is having to work overtime to condition the power to the GPU (Mind it steps down 12V to like 1.1 volts, and has to maintain that under wildly varying power demand conditions)
After that, check...