I'm going to assume you're working with an All-in-one type cooler (I believe they were selling retail versions of the 81xx series with AIOs roughly equivalent to an Antec kulher 620).
Has this configuration been set up for a while, and worked okay? Or, was it just installed / re installed? And, Forgive me for asking, but why would you think the graphics card has something to do with the current issue?
If it's the latter, firstly clean out the radiator, then check to make sure the pump and fans are working properly (fans pretty easy for visual inspection. Pump, either audible, or they usually have a tachometer and the output can be read in bios or with software installed in the OS.
If it's the former double check to make sure your pump and fans are plugged in properly and test. If it keeps running hot, pull the block, clean up all the existing TIM till both block and heat spreader are totally clean. Re-apply your thermal goop of choice (I would suggest using a simple application method. for example, small dab in the middle the size of a large grain of rice, or lentil) re-seat your block and keep pressure on it as you're securing it to the brackets / back plate.
Test again, and if that isn't working it very well may be time to acquire a new cooling solution for your CPU.
Best of luck to you, I hope you're able to resolve this issue.