The ATA’s Technology & Maintenance Council (TMC) offered valuable tips for properly identifying different heavy-duty diesel engine coolants during a webinar last week.
According to TMC, more than 40 percent of all diesel engine downtime is caused by cooling system problems. Today’s coolant varieties are formulated to operate within specific engines, and feature unique inhibitors (organic and inorganic, conventional and extended life) that each provide protection against different issues found in the engine, says Marty Martinelli, national account sales manager, PEAK Commercial & Industrial.
“Those protect the metals from rusting and corroding,” Martinelli says.
During last week’s webinar, Martinelli and TMC detailed how vehicle owners and aftermarket businesses can better identify different coolant formulations based on its color recommendations*, and provided descriptions on the differences between each formulation.
TMC describes today’s heavy-duty diesel coolants as follows:
Conventional: These coolants feature inorganic acid technology (IAT), and lack hydrogen and carbon. They are low silicate blends, and require the manual addition of supplemental coolant additives (SCA) at a first maintenance interval. This coolant is typically green in color.
Conventional fully-formulated: This IAT coolant has a slightly longer life cycle than regular conventional coolants. They are pre-charged with SCA, and are phosphate free. This coolant features a purple/pink color.
Organic: These Carbon-based coolants feature organic acid technology (OAT) and can be formulated with more than a dozen possible inhibitors, nearly all of which are designed to offer long life, good metal protection and improved heat transfer within an engine. This is a red coolant.
Nitrite Organic: This nitrite-rich coolant is formulated with OAT, and does not require an extender supplement until 300,000 miles. It is typicially blue in color.
Hybrid Organic: This coolant uses inhibitors found in both IAT and OAT coolants. It is low-silicate and features nitrite, and requires SCA addition at a first maintenance interval. It is regularly orange in color.
* Though most coolant manufacturers adhere to TMC’s color suggestions, there are no formal rules regarding coolant color in the heavy-duty marketplace.