Is my heat sink working correctly?

[superotter]

tl;dr - My heat sink is scalding hot directly over the processor, but an inch or two away, before it reaches the fan, it is room temperature. Is my heat sink damaged?

Update - See my post below, the heat pipe connecting the processor and sink was broken, the fluid inside of it had leaked out. Buying a new heatsink/pipe apparatus from HP for $40 solved the problem.

Backstory:
I started to have overheating problems on an HP Envy 17" m7-k111dx laptop that had been working fine for a year and a half. When I say "working fine" - I never measured the CPU temps before, but i could play processor intensive games (Civ 5, Witcher 3, etc.) without interruption or slowdown (there is an NVIDIA 840M GPU as well in the machine - I always thought it was a separate card from the motherboard but it shares a fan with my processor, uses the same vent, and is located on the motherboard. I also have a standard intel graphics display adapter).

A few weeks ago, I noticed the fan would be running loud when it was idling, I identified that a Windows Defender scan was causing it, but still found it odd that a security scan could cause the cpu to heat so much. From that moment on, I noticed serious performance problems with games and sometimes the machine itself. I download CoreTemp and saw that the cpu is idling around 60-70 degrees Celsius, when I play games, it will spike to 95 degrees plus and then I assume delays instructions/shuts down until it cools so that the games become choppy and unplayable. In a game like Civ5, the mouse can become very delayed while this is happening, even if i tab out of the window and try to use a different program like Chrome.

So, I started to investigate and saw hoards of advice that I should reapply the thermal paste. I did that several times, to no avail. Each time being more and more careful that I was following the guidelines for application: Cleaning with 91% isopropyl alcohol first so that the surfaces had no residue at all on them, applying not too much thermal paste, a water-droplet sized dot in the middle, then I tried the vertical line method, etc.

Each time, it resulted in very little improvement (idling temps dropped from 70 degrees to 65 or so).

So in a last ditch attempt to try to figure out where the problem was, I opened up the machine as it was running hot, and touched my finger to the heat sink directly over the processor. Ow! It was very hot! So then I touched the heat sink about an inch and a half away, well before it reaches the fan and cooling fins, and it was room temperature. That didn't seem right to me - I know that it should gradually get cooler along the heat sink as it approaches the fan, but it wasn't hot at all,

The air that comes out of the fan is warmish, but not sauna-hot like I've felt before on other machines that were running too hot. Is my heat sink broken? What could have caused it?

Any advice instructions will be appreciated.

 

[AMURR]

have you cleaned it for dust?

 

[superotter]

have you cleaned it for dust?

Are you asking about the fan and sink? The first time I opened it I took a can of compressed air to it, though there was very little dust.

 

[superotter]

tl;dr - No, lol, that part of the pipe should not be room temperature. The heat pipe was busted.

So the thing I was talking about and labeled on my picture is actually the heat pipe (part of the heat sink apparatus) and is used to transfer heat from the processor to the heat sink/fins at the vent of the laptop.

It was indeed compromised. A leak of the heat transferring fluid located within the pipe occurred at some point rendering the heat pipe pretty useless. I bought a replacement heat sink/pipe (they're soldered together) from HP directly and installed it, and voila, my cooling is back to normal.