Let's look at the design difference.
A PC cooler is built for a smaller scale. The fins and coils are close together, designed to be cooled by a small fan.
A car radiator has its fins and coils a ways apart. It is designed to let a lot of air pass through it.
Most car radiator are bigger than your PC; a house fan like a 20 inch box fan would work well with one. It is possable to make a system like this that doesnt look ghetto, but it will take quite a bit of work. And will not fit in your PC case.
A car radiator can be used to cool a PC, but that is not what it was designed to do. There are better choices out there that are more efficient, easier to use, cheaper, and more closely fit this application.
Last edited by Luke Cool; 04-08-2019 at 12:45 AM.