What is Electrolysis?
Most people who own a Classic don't even know what electrolysis is or that it's a condition to be monitored. Electrolysis in an automotive cooling system can be hazardous to the lifespan of metal and in particular aluminum.
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Does your Classic have an aluminum intake manifold? This '67 Corvette Tri-Power version is worth $1,000's |
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Electrolysis has eaten through the aluminum intake manifold to the intake runners |
It is often left unnoticed until it is too late and leaks have already started to form. It's caused by current passing through the coolant medium in the cooling system. This sometimes happens after adding an aftermarket part or breaking a ground, and can be fixed by repairing it. To correct this type of electrolysis, the part or connection causing the excess current must be found and repaired. Check the manufacturer’s manual for TSB's, specifications, and procedures. Why it can be rather devastating to older cars is because of the body on chassis design vs unibody construction.
How Do You Know If Your Classic Has an Electrolysis Issue to be Corrected?


How Do You Fix It?
There are a number of things which can be done to slow down electrolysis, such as re-installing missing or broken ground wires (which we recommend no matter what) using a sacrificial anode (typically attached to a radiator cap) along with yearly coolant replacement. But the most productive method to address is a modern waterless coolant. Here are two videos from Jay Leo's Garage covering the topic.
Waterless Coolant
Plus This Update
To learn more about Evans High Performance Coolant, visit their website.