I read somewhere along the line that electrolysis at a low level occurs in the cooling system. With a high impedance voltmeter, connect black to ground and put the red tip into the coolant closest to block or radiator you can, although it does seems to work with the overflow tank. I read different limits, couple of postings say .2V is max and one said .3V.
Tests should be done with engine running and accessories on too just in case there is excessive current running through the metal of the cooling system. If the voltage goes down with the motor off, then you have a grounding problem.
I ran tests on 4 cars (highest V noted, 1-2 factory fill, 3 not sure)
1. 4 years old, ford 5.4 (yellow) - 60Kmi
2. 6 years old, ford 5.4 (green) - 30Kmi
3. 7 years old, gm dexcool - 85Kmi
4. 40 years old, ford 289, glycol, last flushed 10+ yrs ago
with only 8K mi on antifreeze.
Results (neg voltage)
1. .095
2. .080
3. .120
4. .270
Did just a radiator flush on #4, got .120V. Put in Autozone green glycol.
Guess it seems to make sense, the lower the voltage, less problems there will be. However, I don't know if there is a correlation to ph levels, suspect there is but can't find any ph paper around here.
Comments ?
Thanks
Tests should be done with engine running and accessories on too just in case there is excessive current running through the metal of the cooling system. If the voltage goes down with the motor off, then you have a grounding problem.
I ran tests on 4 cars (highest V noted, 1-2 factory fill, 3 not sure)
1. 4 years old, ford 5.4 (yellow) - 60Kmi
2. 6 years old, ford 5.4 (green) - 30Kmi
3. 7 years old, gm dexcool - 85Kmi
4. 40 years old, ford 289, glycol, last flushed 10+ yrs ago
with only 8K mi on antifreeze.
Results (neg voltage)
1. .095
2. .080
3. .120
4. .270
Did just a radiator flush on #4, got .120V. Put in Autozone green glycol.
Guess it seems to make sense, the lower the voltage, less problems there will be. However, I don't know if there is a correlation to ph levels, suspect there is but can't find any ph paper around here.
Comments ?
Thanks