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Old 02-24-2004, 05:06 PM
RockinWagin RockinWagin is offline
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Join Date: Feb 2004
Location: Double Oak, Texas
Posts: 296
Originally posted by ericnguyen
Dear Leathermang:

You can get a quick measurement of the pH level of a test sample (e.g. antifreeze) by using pH Litmus Paper Strips that can be ordered online (quite inexpensively). The strip of appearing colors shows you the approximate pH level.

Regarding the electrolysis problem in radiators: by definition, electrolysis is the process in which an electric current flowing through a water solution of a chemical breaks that compound up into its components. You can easily observe the effect of electrolysis by doing this simple experiment: add some salt (sodium chloride - NaCl) to 1/2 cup of water and dip the + and - posts of a 9V battery or 12V DC power supply into the salt mixture. You will smell the pungent odor of chlorine gas emanating from the salt mixture.

Similarly, when electrolysis occurs, the various corrosion inhibitors in antifreeze are subject to breakdown and deterioration, thus partly or completely losing their anti-corrosion capability. Therefore, electrolysis is quite a serious problem when it takes place. Electrolysis occurs when electrical current routes itself through the engine's antifreeze coolant mixture in search of electrical ground. In order to test for electrolysis, try to connect the negative probe of a digital D.C. voltmeter to the battery's negative terminal, then submerge the voltmeter's positive probe into the coolant in the expansion reservoir tank without letting the positive probe to touch any metal contact. Now check the voltmeter's reading, it should be than 0.1 V. Any higher value would indicate a serious potential difference across the antifreeze coolant mixture, because the voltage is now high enough to trigger accelerated electrolysis into action, which may destroy the anti-corrosion capability of the coolant. You know what would happen if there's no anti-corrosion stuff in your coolant system. Without corrosion inhibitors, ions such as H+, OH-, H3O+ would start ripping metal atoms from your radiator, heater core, and other metal surface within the coolant system.

In case that the reading indicates a higher voltage, try to disconnect one electrical component or accessory step by step at a time while watching the voltmeter. When the voltage reading drops to zero, the just disconnected electrical component is the culprit for the defective or missing ground.

In summary, if the electrical system and all its accessories/components are working properly, there's no concern about electrolysis in your coolant system. However, electrical gremlins are often quite a perennial problem in a modern car. If the radiator is not properly grounded and some electrical components have a defective ground, a serious potential difference may be established across the antifreeze coolant mixture, kicking the electrolysis process into high gears.

So, does this have anything to do with the use of green antifreeze? Alll recent antifreese that I have purchased have looked more orange than green. I have never gone back to MB to get antifreeze.
1984 300SD 326,997 miles and counting . . . No wait, my odometer is still dead
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