Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

SolSynarchy

macrumors newbie
Original poster
May 24, 2020
3
0
It seems common for these machines to shoot up to 90C+, (in my case it is triggering the "overheat" warnings from HW Monitor).. I've seen theories that the fluid has leaked out of the heat pipe, and noticed many posts across the internet of people who have this problem despite replacing thermal compount (as I have with Arctic MX-4).
My hypothesis is that the heat pipe is simply not "tuned" to vaporize the fluid until around 80-90C. (If you don't understand heat pipe tech, you might need to study up on it for this to make sense.)>
I think that Apple may have done this to create the "silent" computer for minimalist applications, and just accepted that the heat pipe wasn't going to do any real cooling until the CPU Die hit 90C.
The prevalence of this condition makes me think it's less a "problem" than it is a design choice.
Further evidence for this hypothesis is that once the computer has hit 90-95C and the fans ramp up, as long as the applications are continuing to load the CPU (80%+ load) the temperatures restabilize to 80-85C.
Since smaller loads cause it to heat up quickly (Notion is the current culprit), but then the maintenance of those loads or even adding another CPU hog does not return it to that max.. So I'm thinking that the heat pipe is designed with a high vapor point, and this is the root of all these issues.
Thoughts?
 

Intenditore

macrumors member
Aug 25, 2018
85
8
I highly doubt. Usual liquid there is... Water! Also you can test it with a hot water and your finger.
I had major problems (aren't solved yet) with 2013 machine and somebody suggested to replace the heatpipe. I've bought it on Ali, replaced, and... Nothing changed.
So I doubts something leaks from the pipe. And I don't know how to solve that overheating issue
I feel pretty unlucky in my Macs experience((
 

SolSynarchy

macrumors newbie
Original poster
May 24, 2020
3
0
Edited for accuracy.*
I'm specifically suggesting that the heat pipe DESIGN of this model is the issue, so I'm not surprised that replacing it did not help. (Although worth trying, I have another used one on the way to see if I get duplicate results. If I get precisely the same behavior then I am one step closer to my hypothesis being a theory)
I'll let you know if I find a solution, but at this point my guess is that it would require an customheat-pipe with a lower vapor point. Since my screen recently went bad, I might just turn this into a franken-mac and put a big aftermarket heat-pipe on it :) I'd imagine this one might help haha..
heatpipe.jpeg
 
Last edited:

Intenditore

macrumors member
Aug 25, 2018
85
8
Basically the most information-intense video regarding how heatpipes are made is this factory tour by Gamer Nexus
And I think about all of them are about the same but I wouldn't bet, sure.

Although worth trying, I have another used one on the way to see if I get duplicate results. If I get precisely the same behavior then I am one step closer to my hypothesis being a theory
Whatever it is, they all are the same, I tried three of them and no difference bieng noticed.
 
  • Like
Reactions: SolSynarchy

SolSynarchy

macrumors newbie
Original poster
May 24, 2020
3
0
Ok, thanks for proving me wrong! I appreciate that more than anything, since it allows me to refine my knowledge. My heat-pipe knowledge came from non-computer related engineering so I am glad to be corrected. So then if they are using distilled water then the phase change point is purely determined by the level of vacuum being pulled.. So a more complete vacuum would result in a lower phase change point.. would be an interesting experiment to pull a deeper vacuum on one of these and see if it affected it.
My hypothesis remains (and it is ONLY a hypothesis) that Apple "tuned" (via vacuum if it's distilled water type) these tubes to be right around 80-90C so that simple convective cooling would handle regular usage and then when the CPU started cranking out heat it would eventually activate the vapor change. My temp monitor routinely shows 80C+ temps on the CPU and die while the heatpipe hangs out at under 50C.. (although we are admittedly dealing with unknown accuracies in the sensors) .. You thread was interesting re: Windows seemingly not causing this fault.. Thanks again
 

mick2

macrumors 6502
Oct 5, 2017
251
237
UK
Pretty sure there's no fluid of any kind in the 2013 MBP stock 'heatpipe'. Its made out of solid copper, with fins and solid copper 'pipes' to transfer the heat to the fins. Same as all other Macbooks, of any year / generation. A more accurate description is 'heatsink', not 'heatpipe'.
 

bitshovler

macrumors newbie
Nov 5, 2018
2
0
yeah, i have two 2013 late macbook pro's on my desk. one i sourced the screen from to use on the other. so one complete a1398 with nvidia gpu whereas the one without the screen is just the intel iris integrated cpu.

some tidbits i find interesting. the extra macbook (just the intel integrated gpu) runs headless as the internal screen has been removed. it runs arch linux and the cpu fan at idle constantly spin at ~ 2000 rpm. as i understand the cpu fans always spin on these models and 2000 rpm is the base.

whereas the macbook with the discrete nvidia gpu my fans spin @ ~ 5000 to 6000 rpm. now this computer is using its internal display along with an external monitor (4K at 60 hz via the thunderbolt port) the cpu fans noticeably spin higher (rpm) when the external display is connected.

however i feel with each update of macos and browser update that the cpu fans on this computer are spinning faster and longer unfortunately, which is unfortunate cause when i first got this computer the cpu fans rarely ramped up. i've replaced the thermal compound on both the cpu and gpu (nvidia) with liquid metal and that has helped over the stock thermal paste, but i'm still disappointed with the rpm of the fan speed.

at this point i'm thinking that maybe adding an extra heat pipe to the cooler might help. 🤷‍♂️ or attempting to add a copper shim of some sort to make sure that the heat transfer to the cooler is optimal. the little spring mechanisms and how the metal just flexes to create a bond is less than ideal. so if i can get better contact from the die of the gpu especially to cooler, adding a copper shim i'd like to think that i could help with my cooling situation.

i open to heat pipe or copper shim. i do have copper shims on hand, but no extra heat pipes. and welding/soldering extra copper heat pipes is kind of pain in the ass (prior experience) to say the least. there is a decent epoxy with good thermal transfer though.

curious in what mods if any people have performed on these computers?
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.