Diesel Cylinder Liner Erosion
When you’re buying a diesel engine, be sure to have the coolant tested cavitation erosion. It’s one of the most prevalent types of failure and will hit you in the pocketbook.
Ray Bohacz is Successful Farming’s engineman. He says on a diesel engine that has what’s called a “wet liner,” the cylinder liner is pressed into the block. The engine coolant goes around the liner between the engine block casting and the liner.
"What happens is when the diesel engine runs, the liner actually vibrates. When it vibrates and the coolant hits it, it creates little bubbles, like in a bottle of soda. And over time, these bubble s have the ability to erode the cylinder liner," says Bohacz. "When that happens, it eats away the metal and then the engine oil mixes with the coolant, and the engine is ruined and requires a complete rebuild."
Bohacz says you prevent this from happening by keeping the engine coolant properly charged with “supplemental coolant additives.”
"A diesel engine needs a special coolant that eliminates the bubbles from forming, and also does not allow them to stick and erode the metal surface of the liner," he says. "That is why it’s imperative that you use a test strip to test the coolant for the additive package that will stop cavitation."
A $25 laboratory test will show any elemental metals in the coolant. If elemental metals are found, this means erosion has already started. You may want to reconsider buying that engine or negotiate it into your price.