APU very hot even after cleaning

[duffman2k]

I have given it a good clean and new thermal paste. Twice. Just to be sure all is tight and the new paste is good. But after a few minutes in idle I get temperature of 70 C and after a short load about 80.
I use a temperature app don't remember the name, but the time it takes to close a game and start the app the temperature might drop.
Is this a known problem? The previous owner mentioned after a few hours of gameplay the PS4 wouldn't turn on for a while, and needed time to cool down before booting again.
I was thinking maybe there is something wrong with the integrated heatink but don't want to delid unless it's a last resort

 

[ShadowMaya83]

I replaced my thermal paste 2 months ago with arctic MX-6 and my idle temps are 58-60 c on idle. With a game running 65-67 at most.

I tried using the temp app but you are right that the temps can drop from quitting the game and going in to check. You can try loading up orbis toolbox. There's a temp overlay you can use to see how high temps are in-game.