Alienware 17 R3 Heat Issues

Let me start by saying that the Dell Support engineers have been fantastic  - I'm just unlucky and have a plagued laptop! 

So the keyboard has been replaced 3 times, battery once, and a new motherboard. Since then games that I normally play with no issues (110 - 140FPS) have dropped to 20FPS and stay there, as soon as I lift the laptop off the table the FPS comes back up. So it's obvioulsy a heat issue. My problem is that before the motherboard was replaced this NEVER happened. I've got screenshots of the CPU getting up to 92 degrees playing Return to Wolfenstein (10 year old game?). I was just wondering if anyone had any ideas? 

My only thoughts were that the thermal paste isn't on properly (or at all) or the power cable to the fan is caught / damaged and therefore not giving enough power to the fan. 

It's got to the point that the laptop is so hot I can't use the keyboard.