I'm working on flushing the radiator on my 2010 Mazda 3 at 10,000 miles.

Am I correct to assume an appropriate process is to iterative by filling and drain the system with distilled/de-mineralized water until the drained fluid appears clear?

I see products such as radiator flush, does this have any improvement above using distilled water such as above and if so when should I use them?

Prestone Radiator Flush

1 Answer 1


In my 1.6 mazda 3 I did it using water and the results were pretty good, I did it at around 45k KM as a preventative maintenance. Before that a couple of years back when I took my other 2.0 Mazda 3 to local dealer he used something like “Purple Cleaner”, honestly I did not see much difference, the later one costed my few hundred extra with almost same result.

I personally find water to be easier option as after first flush you can drain it directly without having to manage multiple containers, secondly from a colour change perspective its easier to make it out when you use water and from a cost perspective it’s cheaper with no visible difference in result.

  • 1
    I'm hoping stackoverflow will with time help us objectively quantify things such as "purple cleaner" My bias is it is snake oil and will use demineralized water inline with your experience until the manufacturers want to join in and argue otherwise. thank you. Feb 15, 2019 at 15:21

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .