- Oct 21, 2015
Hello folks. Has anyone done a voltage test on their coolant to test for additive depletion/electrolysis? I ran across this test on a few YouTube videos and internet sites. Basically, you measure the voltage between the coolant and the negative lead of the battery. Some sites say 0.3V or less is good and other say it should be much lower. https:/
/ (change above 0.07V)
https:/ www.youtube.com/ watch?v=mBXZtfzHhig / (change above 0.33V)
http:/ www.youtube.com/ watch?v=x-gceYx_3RE / (change above 0.3V)
So I was planning on doing a coolant change and when I ran across this test I tested the old coolant. I only got 0.005V (and noted the voltage dropped to zero within seconds unless I "stirred" up the fluid a bit again) . I also looked up the change interval in my factory service manual, I noted it says to change the green coolant every 30k or 24mo and it has been way over 24months, but also way less than 30K (probably 15-20k).
So, I'm wondering:
1. why the discrepancy between these threshold values for good and bad coolant?
2. have I done something wrong in the test that I only got 0.005 volts (note I did it with engine cold and not running and ignition completely off - some sites say you should conduct the test with engine warm and running). Also I have a very inexpensive DVM from Home Depot but it works fine for checking my hobby LiPo batteries and the like.
3. is it possible the coolant formulation has changed since 1995 such that these coolants last much longer than 30k/24mo and the reading is truly accurate? I know this is true for engine oil quality which has certainly changed in 23 years!
Very curious what values other folks have measured (if in fact anyone has!).
Thanks! www.ve-labs.net/ electrolysis-101/ how-to-test