AMD 7870 Overheating?

[igounknown]

So I custom built my pc mid 2013 and i've never had any issues with overheating. I Started playing a zombie survivor game called h1z1 which is still in alpha about 8-10 months ago. All was fine til about a week ago, every time i boot the game, a strange humming noise comes from the psu, and the temp of my graphic card goes from an idle of 50-55c to upwards of 90c just at the main menu. When i attempt to load into game the temp begins to rise to upwards of 100c then my pc flashes off then comes back on. But this only occurs while play h1z1 and happened just recently, previously logged over 1000hrs before the issue. Would this be caused by my graphics card or my psu? I would assume its my graphic card going out but im not sure, any help would be greatly appreciated

 

[clutchc]

Yes, that's too warm. Might be old dried out thermal paste that needs cleaning off and replacing.
http://www.newegg.com/Product/Product.aspx?Item=N82E16835100010&nm_mc=KNC-GoogleAdwords-PC&cm_mmc=KNC-GoogleAdwords-PC-_-pla-_-CPU+Thermal+Paste+%2F+Grease-_-N82E16835100010&gclid=CPK98Ni7vMoCFQanaQodQwACSg&gclsrc=aw.ds
http://www.newegg.com/Product/Product.aspx?Item=N82E16835186038

What is the make and model of your PSU?

 

[nikolakuzmanovic]

Try it with a different PSU, if that does not help, remove the gpu cooler and heat sink clean them out from dust and add a fresh layer of thermal paste onto the gpu, thats what i did, same issue with overheating.