Using an Old Car Radiator to Cool a PC

The easiest way to enter the world of watercooling is through AIO products, which already include all the necessary components in a closed configuration. However, liquid cooling can achieve superior performance with custom designs that allow us to modify the number of fans and the radiator size. Now, what would be the absurd extreme to cool a PC with such a system? The answer is using an old car radiator...

When it comes to cooling a computer, all you need to do is dissipate the heat from its components into the environment. How? Generally speaking... any way possible. Aluminum and/or copper blocks, fans, mineral oil immersion or Novec fluids, and of course, liquid cooling. Heat is transferred to water and then dissipated in a radiator, although we've seen some exceptions in the past.

Logically, the main trick to improve the performance of a custom watercooler is to increase the radiator size. More surface area, additional fans, and extra liquid mass combine to reduce temperatures even further. So... what's the limit? How big can the radiator be? If there's a person willing to do such an experiment, it's Linus Sebastian and his team at Linus Tech Tips:

How to Use a Car Radiator to Cool a PC

It all starts with the radiator from a 2009 Chrysler PT Cruiser, which they bought for 170 Canadian dollars (about 112 euros). After flushing the radiator and determining the direction of its loops, the next step was to create an aluminum 80/20 structure, and add a total of nine fans using zip ties.

The most complicated part in this kind of project is adapting the radiator connections to the hoses in the system. Using a bicycle inner tube as an "interface" is an interesting solution, but imperfect. When liquid was introduced into the circuit, leaks appeared immediately at various points. From there, the project becomes a race against time, the leaks, and the need to add extra fluid to the pump.

And It Works Very Well

Despite moments of desperation and all the improvisation... it works! The hottest core of its Core i9-10900K dropped twenty degrees (60C at 100% load at 4.9 GHz all-core isn't bad at all), while the GeForce RTX 3090 installed in the computer went from 60 to 35 degrees. The most striking thing is that the public is asking for a cleaner and quieter version, with proper connectors and without the madness of adding fluid every 30 seconds. Will there be a part 2?