Why does my MacBook sound like it wants to take off?
Spoiler alert: Maybe it’s full of dust?
I’ve seen an increasing number of chats online about laptop fans ‘blazing’ while running Zoom calls, sharing Miro boards, or running lots of concurrent software apps. With many people losing their jobs, and many freelancers short of work at the moment, it’s maybe not the ideal time for some to be upgrading to a new laptop.
Add in that (at the time of writing), most authorised repairers and Apple Stores closed due to Covid-19 restrictions, if you’re suffering from a noisy, slow and hot MacBook, you might be wondering what to do. I had a long-running issue with my MacBook Pro running hot, and finally managed to solve it, after quite a bit of head scratching.
Running hot
My trusty 15” Macbook Pro is nearly five years old. I bought it just before the first generation Touch Bar launched, and by all accounts I got myself one of the last ‘good Macbooks’. It was a top-spec model, and has had a replacement screen as part of the staingate recall. So I’m not ready to chop it in just yet.
However, I noticed the cooling fans were getting louder, and spinning up for much longer. And the aluminium casing was getting hotter, between the keyboard and screen hinge. At first I didn’t pay much attention to it – I was in the middle of a short-term contract, and the internal design team all had current generation MacBook Pros, which frequently sounded like they were ready to take off. But a couple of months on, the fans were still spooling up on mine, and I could nearly fry an egg on the casing!
Tracking down the issue
I decided to get someone to look at it. But then lockdown was announced, and everywhere shut overnight. I realised I was going to have to figure this out myself.
I’d been running Activity Monitor for a while to see what was happening. I’m guilty of keeping too many browser tabs open, and running multiple apps at once, which was hogging the CPU (especially in Chrome). But managing this hadn’t fixed the overly-eager fans. I upgraded to the full version of Clean my Mac, and ran all the scans available. Then I ran a virus checker. I reset the SMC, and finally ran Apple Diagnostics to test the hardware, as I thought by now it must be a physical issue. Everything checked out ok. Maybe it was just getting old, and I needed to buy a new one after all.
“Have you cleaned the fans yet?”
A chance conversation with a technically-minded friend threw up this question. It hadn’t even occurred to me. I mean, how do you clean the fans? I searched online and found the video below, and then purchased an basic toolkit from iFixit.com (which features in the video and is excellent). I also got a can of compressed air from Amazon. You can get the same toolkit on Amazon too, and save on shipping costs, but I tend to think Jeff has enough money these days.
Opening up the Patient: Part 1
I turned the power off and backed everything up, then removed the underside cover. I was pleasantly surprised when I saw inside. It was pretty clean for five years old. I’ve seen videos where they open a year old MacBook, and it looked like the contents of a vacuum cleaner had been dumped in there. However, the fans in mine were clearly in need of a clean.
Top tip #1: Make a note of what screws go where, when removing the casing, as two of them are smaller than the rest.
I used the compressed air (in very short bursts) on the fans, taking care not to touch anything, but I discovered later that this wasn’t the best thing to do. As fun as it was to watch the fans spin round while blasting out the dust, it ran the danger of damaging the motherboard – something to do with reverse polarity?! Thankfully I got away with it.
Left: fan before cleaning (pretty gross). Right: after cleaning.
Top tip #2: Hold the fans still when cleaning them, especially if using compressed air. Or use a small brush instead.
I was pretty pleased with the results. It looked like a brand new Macbook. I fitted the case back on, ensuring the screws went in the right holes and I didn’t over-tighten them. There’s also a couple of clips inside that require a gentle push around the centre of the casing. You’ll hear each click into place.
I definitely noticed a difference in the fans at this point. They weren’t cutting in as often, or for as long. And the noise was definitely quieter too. But it was still running hotter than I’d like. Regardless of this, I posted up my minor triumph on Twitter, as you do, and got this response…
“Did you change the thermal paste?”
The thermal what? I had to look it up. It turns out, computers have a special paste applied to the CPU and GPU, designed to help transfer excess heat onto the heatsink. Over time, it dries out and becomes useless. Who knew that? It turns out my new lockdown skill of becoming an ‘Un-Authorised’ Apple Repairer was not going as well as I’d thought. I went back to the iFixit store and ordered Arctic Silver ArctiClean and Arctic Silver Thermal Paste.
Opening up the Patient: Part 2
I found the following Thermal Paste Replacement video (apologies for the irritating soundtrack), and got to work.
Removing the heatsink is fairly easy, but keep a note of what screws you remove from where. You’ll also need a different screwdriver attachment to remove the internal screws, which is included in the toolkit I mentioned before.
Before cleaning: CPU, GPU and heatsink with original dried thermal paste.
With the heatsink removed, I could finally see the CPU and GPU, and the dried-up factory applied paste. I followed the instructions of the paste remover, putting a few drops onto the old paste. Once I’d removed it all, I applied the surface purifier to clean and prep the CPU/GPU and copper contacts of the heatsink. So far, so good, it was now time to apply the new paste.
Top tip #3: Paste remover stinks! Make sure you’re in a well ventilated area. It’s also really messy, as it turns the dried-up paste into wet goo pretty quick. And use a microfibre cloth so you don’t leave any lint behind that could get stuck within the components.
After cleaning: CPU and GPU surfaces ready for new thermal paste.
The paste comes in a tiny plastic syringe. The videos I’d watched recommended a ‘pea-sized’ amount on the main CPU, and a proportionate amount on the smaller GPU. It was a lot thicker than I imagined it to be, and it did have a tendency to go a bit stringy as I lifted the syringe away, so care is needed here. Don’t be tempted to apply too much as it will cause more overheating issues.
Once applied, and spread evenly over the correct areas, I could screw the heatsink into place, and then finally replace the main case. But had it worked, or had I irrecoverably ruined my Macbook? Time to flip it over and switch it back on.
Note: In a mix of mild panic and concentration, I completely forgot to photograph the new thermal paste I’d applied, but you can see what to do in the above video.
Thankfully my MacBook started up ok, and I immediately started to check for any differences. According to Clean my Mac, the CPU was running almost 10ºc cooler than before, when I tested it out with similar tasks. After nearly a week of running, I’d definitely experienced a massive reduction in the amount of times the fans kick in, and for how long they run. And it seems a little faster too.
Summary
In total, I spent just under £60 including p&p, and have almost certainly improved the performance, as well as the longevity of my MacBook. So all in all, a pretty cheap upgrade considering the alternative. And I attempted something I’d never have contemplated before, which in retrospect was a lot simpler than I imagined.
Thanks for reading this far. Hopefully some of this waffle was helpful to you.
Top tips and reminders
Avoid using your laptop on fabric surfaces (on your lap, in bed etc) – it only allows more dust to be dragged inside
If you have pets, or work in a dusty environment, your laptop will require cleaning more often
Be careful using the compressed air near the fans – hold them still or use a small brush instead
Never use a vacuum cleaner to clean the circuits – this will create too much static discharge
Thermal paste remover stinks – use in a well ventilated area, and don’t apply too much!
Back up your laptop up before you do anything.