Dealing with the effects of Automotive
Electrolysis can be a very aggravating. It is a cruel and demanding
teacher, and has a steep learning curve.
However YES, there is hope! The good news
is that Automotive Electrolysis is governed by the laws of physics,
and behaves in predictable ways. If we can understand a bit about
how it works, we will be able to get the upper hand on this problem,
stop it in it's tracks, and send it packing .
Please continue reading and learning about Electrolysis on our
continually updated knowledgebase located here:
VoltageDrop. You will find
articles, photos, how-to's and products designed specifically for
helping you survive your exposure to Electrolysis. Whether you are
an Automotive Repair Shop, Feet Service Coordinator, or an
Individual Vehicle Owner, the solutions to you Electrolysis Problems
are known, published, and available.
Electrolysis Knowledgebase located here:
ELECTROLYSIS: THE SILENT KILLER
According to the dictionary, electrolysis is:
1) Chemical change,
especially decomposition, that is produced in an electrolyte by an
2) An electrochemical process by which electrical
energy is used to promote chemical reactions that occur at
What is electrolysis and why is it a problem in an automotive
cooling system? Lets start by trying to understand electrolysis as
it pertains to automobiles. Electrolysis is a destructive force that
packs enormous potential to damage not just cooling system
components, but any aluminum engine part that has contact with the
coolant. The coolant acts as both the catalyst and as the conductor,
just like the electrolyte in a battery. The "electrodes" mentioned
in the above definition are the aluminum components in the cooling
system (like the plates in a battery). The "electrochemical process"
mentioned is the aluminum particle (ion) movement, such that leaks
(thinning of wall surface) occur. When enough ions have moved, this
results in a failure (leak) typically in the radiator or heater due
to the thickness (read thinness) of the tube wall surface. A thicker
surface (like an aluminum casting) is not more resistant to
electrolysis, but is not as likely to leak because it is thicker.
However these thicker surfaces may leak anyway if the electrolysis
occurs at a gasket surface. Generally you won't know you have an
electrolysis problem unless you have (a series of) unexplained
leaks. However, to add yet another factor, in some parts of the
country (southwest), electrolysis is much more prevalent than
Fact #1 Electrolysis will manifest itself with unexplained
coolant leaks in thin walled aluminum components, typically the
heater or radiator, whichever may be electrically more attractive to
the ion movement.
Can electrolysis be measured? At the heart of the electrolysis issue
is it's measurement. If it can be measured, it's presence can be
verified, which is extremely important when we are removing the
electrolysis. More than half a volt!
It is a simple measurement, a digital VOM is needed, simply attach
one lead to the negative battery post, and with the other, dip it in
the coolant. Should read zero right? Maybe just a bad ground? Try
this, remove a battery post. Still reading .3v or above? It's not a
loose ground your after.... You better keep reading.
Fact #2 If you have a reading of more than .3v, (three tenths),
you have electrolysis. Generally, a reading of hundredths (.01-.09v)
is below the action level, and will not result in aluminum failure.
Can Electrolysis be prevented? Absolutely! The key to the prevention
of electrolysis is to understand the cycle. If we can remove the
electrolyte, the process can not occur. But isn't the electrolyte
the same thing as the coolant? Yes, and no.
Fact #3 When the coolant gets acidic will it act like an
electrolyte, and set the stage is set for electrolysis to occur, and
the destruction of thin aluminum components to begin. So how does
coolant get acidic? In the early '90's the recommended service
interval for coolant was 24 months. When changed at this interval,
the coolant was removed before it was "spent". It still had good
color and was still protecting the metals with corrosion inhibitors.
When changed, all the old coolant mix was purged, along with any
small amounts of acidic build up. As a result, electrolysis in the
early 90's was extremely rare.3 Beginning in 1996, with the
introduction of Dex-cool, the recommended service interval of
coolant grew to 5 years. New developments in chemicals and a
changing maintenance strategy has fueled these advances that are
tested in laboratory conditions and on vehicle fleets. Unfortunately
the successes in the laboratory have not always directly translated
to a success in the field. It is not surprising that electrolysis is
now a major under hood problem. Another factor is the increasingly
tighter environmental restrictions on flushing and disposal of
automotive flush water. "Can't just flush'er out like
we used to do".
Fact #4 Longer maintenance cycles allow the coolant time to
decompose, loose it's protection, and get acidic. As the existing
metals in the cooling system are now "exposed" to an increasingly
strong electrolyte, ion movement begins to occur. Ion particles are
whisked away by the fast flowing coolant,
This stuff is packin' almost .6v
the block, so that even when the coolant is finally changed, the
acidic nature remains. Too little too late.
Fact #5 If you want to prevent electrolysis from taking hold, the
time proven flush and fill is all that is needed, as long it done
before coolant decomposition begins. However, once electrolysis has
taken hold, a simple flush and fill just isn't enough, and more
drastic measures are called for.
How do we get rid of electrolysis? Since automotive electrolysis is
a chemical problem as mentioned above, the answer to ridding
ourselves of this problem will be to neutralize the acid. In
addition we need to remove the spent antifreeze, remove any metal
particles in the deep reaches of the engine block, and "scrub" the
internal surfaces of the block. Sound like a flush to me. But not
just any flush. We need to REALLY flush this thing out. We first
pull the thermostat out, connect our flush machine4 and let run.
Sometimes we flush for as long as 36 hours. Once the flushing and
rinsing is complete, new antifreeze and fresh water (50/50 mix) is
installed with a new thermostat. Generally distilled water is not
used, as it tends to be "hungry water" looking for ions. A chemical
additive is then added to help in a variety of ways. It will control
pH, help the coolant to remain non conductive, and contains an
oxygen scavenger to prevent cavitations, erosions, and pitting. Last
but not least, a sacrificial anode is introduced into the cooling
system to "pull" any stray electrolysis away from aluminum
components. Don't forget to retest for voltage in your cooling
system. If you have more than .1v (one tenth), your not done
flushing! For access to these electrolysis products click here.
There are plenty of good uses for electrolysis, such as in the
plating industry, where the goal is to move metal particles from one
surface to another. Gold plated emblems and jewelry are successful
applications of electrolysis. Of course another type of electrolysis
is hair removal. Altogether different, and discussed here.
Industrial applications of electrolysis include the manufacture of
aluminum, and lithium, and hydrogen for hydrogen fuel cell vehicles.
Other commercial applications include the manufacture of aspirin.
But in an automobile cooling system, electrolysis will only give us
If electrolysis has always been around, why is it such a big problem
now? It used to be that the difficult electrical problems consisted
of shorts, opens, and draws. Now we have to worry about reference
voltage, bus speed, and thermo resistors. Secondary spark voltages
are only increasing, A/C and D/C currents and EFI signal amplitudes
add an aggressive neutron and proton cocktail where water conducts
electricity by the movement of ions in the increasingly at-risk
cooling system. In an unprotected cooling system these neutron and
proton atoms magnify the strength of the electrolyte infected
coolant. 2 With more and more aluminum components under the hood,
and in the cooling system, longer maintenance cycles and more stray
electrical energy, it's no wonder it's a problem.
How to lose a customer is a informative article written for the
automotive repair shop dealing with the electrolysis issue. In
addition to the technical aspects of electrolysis, it touches on the
warranty issues of failed parts due to damage caused by the
electrolysis. "If only I had read this first....."
Improper coolant a short informational sheet from Performance
Radiator discussing the proper coolant and water requirements.
Electrolysis problems increase is a short reprint article covering
the highlights of electrolysis detection and repair.
Electrolysis pictures pictures taken of vehicles at our shop that
have experienced electrolysis related failures, and repairs.
1 The American Heritage® Dictionary of
the English Language, Fourth Edition
2 BMR Distributing Interject Electrolysis Arrestor.
3 Speaking for our experience at San Carlos Radiator.
4 Proprietary process.