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Finally, Air-cooled G5 Quad
Posted by: AndiS on 2026-08-17 15:08:34 A few years ago (time flies) I got a G5 Quad that was still running although a bit hot. While I tested it from time to time, I always feared a leak in the cooling system but also its complicated restoration. I almost wanted to sell the G5 to someone less fearful, but before that I searched once more for strategies to deal with the problem. Well what can I say - I found this awesome guide and after getting the few needed parts my G5 Quad is now air-cooled and humming along cool and quietly. No leaks yet although it was the rather notorious Delphi Cooligy variant. I found the whole process quite easy and straightforward. Would recommend!
Posted by: Unknown_K on 2026-08-17 15:30:32 Did you keep the old liquid cooler? I figure somewhere down the road people might want to modify them with new technology and will need the old parts.
Posted by: AndiS on 2026-08-17 16:02:41 Of course I did. Looking at it rebuilding should be much less complicated than I feared before I opened the G5. But still - everything with liquid makes me uneasy around electricity. I'll sleep much better now ;-)
Posted by: treellama on 2026-08-17 17:08:50 What kind of temps are you seeing? Mine with the mod will go into the high 60's/low 70's under load, which brings the intake and exhaust fans up to be quite loud. Then drops back into the mid 40's and eventually quiets down. But it's only really quiet when idle.
Posted by: Unknown_K on 2026-08-17 17:43:59 Of course I did. Looking at it rebuilding should be much less complicated than I feared before I opened the G5. But still - everything with liquid makes me uneasy around electricity. I'll sleep much better now ;-) I have stacks of machines but only one water cooled one because of my fear of leaks plus not knowing when the coolant gets fouled and stops pumping.
Posted by: AndiS on 2026-08-17 22:07:14 But it's only really quiet when idle I have to do some more testing but in my case the idle values are around 35-37 Celsius while the wherre in the mid to high 40s before the mod. Of course it will be much louder when the CPUs are stressed - it was only a bit late already yesterday. I will report test values.
Posted by: gsteemso on 2026-08-18 06:39:48 Thanks for posting this! I don’t (yet) have a Quad, but I’ve been semi-seriously keeping an eye out for one with the intent of performing this conversion. This will help a lot!
Posted by: treellama on 2026-08-18 06:55:23 You can see my adaptation to the mod for mounting the fans to the coolers in a more durable way than duct tape (lol): https://forums.macrumors.com/thread...-g5-quad-to-air-cooling.2457994/post-34384384 A 3D printed bracket to hold them on there would be even better...maybe some day.
Posted by: AndiS on 2026-08-18 14:06:15 It is not only duct tape but also cable ties and at least one clamp on each cooler. The duct tape is more a statement because every successful project needs the right amount of duct tape ;-)
Posted by: quadra700 on 2026-08-27 22:58:31 I came across that guide late last year and have been looking for those heatsinks since. They have not been easy to find but I actually just found them recently, the 2nd being delivered only a few days ago. Ive had my quad for years now but have never used it out of fear of what happened to krazy ken. I did power it on when I first got it and tested it briefly but that's it. I'm excited to do this mod and finally enjoy this machine. Also going to be converting a dual single core 2.5 using stock 2ghz heatsinks.
Posted by: quadra700 on 2026-08-28 15:33:02 Oh, great. Just as I want to start getting into this project, the site guide is no longer loading 🙄
Posted by: alectrona6400 on 2026-08-28 16:33:19 i did this project too! saved a machine that wouldn't boot because of a dead water cooler. and of course made it actually usable again...
Posted by: quadra700 on 2026-08-30 17:12:36 i did this project too! saved a machine that wouldn't boot because of a dead water cooler. and of course made it actually usable again... Which nylon spacers did you get? The guide doesnt specify so I got some at home depot measuring .171" x 3/8" (inner diameter) x 1/4" (outer diameter) and they seem too tall, the nuts dont reach the threads on the guide/mounting posts. Also, the "knurls" mentioned in the guide dont fit those mounting posts at all. I wonder if the person who made the guide forced them on? I was hoping to have this done this weekend but looks like Im gonna have to put in another amazon order
Posted by: treellama on 2026-08-30 17:31:19 I had to cut my nylon spacers down to the right height with an X-acto knife. The knurls do fit the mounting posts but only with maybe less than a turn if I recall right. I didn't have to force them, but they don't turn on very much. Just barely enough to hold, don't transport your G5 through the desert on a jeep.
Posted by: alectrona6400 on 2026-08-30 18:33:06 Which nylon spacers did you get? The guide doesnt specify so I got some at home depot measuring .171" x 3/8" (inner diameter) x 1/4" (outer diameter) and they seem too tall, the nuts dont reach the threads on the guide/mounting posts. Also, the "knurls" mentioned in the guide dont fit those mounting posts at all. I wonder if the person who made the guide forced them on? I was hoping to have this done this weekend but looks like Im gonna have to put in another amazon order i got ones off amazon, don't remember the size but they were close to the ones documented in the guide.
Posted by: AndiS on 2026-09-12 13:20:21 In my case I just printed some spacers with a 3D printer after some measuring and judging the correct heigt. Easy.
Posted by: quadra700 on 2026-09-19 16:28:27 I ended up doing the same, 3d printing spacers. Got both my quad G5 as well as my dual single core 2.5 air cooled now. Unfortunately I did lose one of the single core 2.5 cpu's to corrosion from a leaking LCS but at least its still working as a single 2.5.
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