As winter descends upon the U.S. with brutal temperatures fast approaching, the importance of preparing a heavy duty engine becomes critical to vehicle uptime. This is especially important for cooling system maintenance. When it comes to freezing – and also summer boilover – the mixture of water and antifreeze/coolant (AF/C) needs to be just right.
Finding the right balance
It is essential to stick to a recommended maintenance schedule and practices as winter weather puts strains on the vehicle’s engine. The functions of AF/C are far more complex than just freeze and overheating protection. The latest technologies in today’s AF/C provide a layered approach to controlling engine temperatures, as well as protecting engine components from premature damage and corrosion.
If the cooling system is unable to satisfy the essential requirements put on it by the engine, the vehicle’s horsepower, fuel efficiency, emissions and overall durability will be compromised. Selecting the highest quality AF/C products and replenishing at recommended intervals will ensure operating efficiency and optimal performance. Controlling as many variables as possible and keeping trucks on the road will directly impact the bottom line of any operation.
The challenge
While the threat of winter freezing may appear, on the surface, to be the primary concern, corrosion mitigation is also a primary function of coolant. Testing the coolant concentration (mixture of glycol, water and inhibitors) is an important part of winter engine management.
Water and a water-glycol mixture alone are naturally corrosive. Coolant manufacturers add chemicals, known as corrosion inhibitors, to the glycol/water mixture in order to prevent the cooling system components from corroding.
The very best coolants will not only protect a heavy duty engine from freezing up in cold temperatures, they also actively fight metal corrosion within the engine. Corrosion, and rust in particular, can degrade the effectiveness of an AF/C system, negatively impacting performance and the long-term health of the engine. Given the multitude of metals making up any engine, it is important to understand the need for corrosion protection.
With the seemingly innocuous decision to merely add water to a cooling system, a heavy duty cooling system can incur significant corrosion from this unintended dilution, as well as a loss of protection, leading to an increased incidence of liner pitting.
While most coolants will protect a heavy duty engine from freezing up in cold temperatures, they also need to actively fight metal corrosion within the engine cooling system. Corrosion can degrade the effectiveness of a cooling system by generating deposits in heat exchangers and negatively impacting the performance of the radiator to remove heat from the system.
Testing coolant levels
Testing coolant levels is essential for protecting a heavy duty engine. If the glycol concentration is too rich or too low, freezing and boilover protection becomes a problem, as can changes in the level of inhibitors necessary to protect the essential engine components.
Fleets running in extreme cold conditions might decide to push the glycol levels to the upper limits (a maximum of 70 percent is recommended) for optimum freeze point protection. Extreme care at these concentrate levels must be exhibited when warm temperatures approach. The coolant concentrate needs to be rebalanced to recommended concentrations of 50 percent to optimize the heat transfer properties of the coolant (the ability to keep the vehicle from overheating).
Excessive levels of glycol and relatively low levels of water create a pool heat transfer environment that will encourage higher underhood temperatures, overall cooling system fatigue and potential engine overheating and failure, while insufficient water percentages can also compromise corrosion additive effectiveness.
Proactively testing engine coolant is essential to making the right decisions for maintaining the correct levels of coolant concentrations. There are a number of testing options that offer the ability to test a wide range of important coolant variables from basic glycol concentration, to far more extensive methods that measure conditions of the fluid and the ability of the coolant to protect the engine from corrosion by measuring the level of inhibitors.
Colin Dilley, Ph.D., is the vice president of technology at Prestone Products Corporation, appointed in 2014. Dilley has been directly responsible for developing and launching several propriety Prestone products, including Prestone’s Cor-Guard corrosion inhibitor technology in the company’s coolant. He holds a Ph.D. in Applied Management and Decision Science from Walden University.
