We have had some smoking hot weather. I am sure you would agree. What better time to do a review on your vehicle’s cooling systems. Yes, systems not system.
The antifreeze/water mixture that the water pump pushes through the engine and out to the radiator to get rid of waste heat energy and keep your engine from self destructing on a hot summer day is not the only cooling system on the vehicle.
There are a few other liquids in various vehicle systems that are also working to keep mechanical moving parts lubricated as well as cool.
Admittedly the engine’s cooling system handles the most heat as it is directly dealing with the waste heat of combustion. Roughly thirty percent of the energy in the $1.40 per litre gasoline you put in the tank exits as waste heat through your engine’s cooling system.
Your engine’s lifeblood, namely the engine oil is also a coolant for your engine. It is part of the engine’s lubrication system. It is not only required to prevent metal to metal wear. It is also tasked with removing heat from the engine by default. As the engine oil circulates it picks up waste heat from friction and combustion.
The system is designed with a sump or oil pan. The size and design of the oil pan is very much a factor in determining how much engine oil is required. There must be enough oil to supply the engine at a certain pressure, flow, and temperature. The extra volume in the oil pan allows the oil to cool before being sucked back up into the pump and sent through the engine.
When you neglect your oil level not only do you risk lubrication problems from lack of oil but also cooling problems. Most vehicles do not report oil temperature but you can be sure when you are running a litre or two low your engine oil is running hotter and once above a certain temperature the engine oil’s lubrication properties are compromised.
Whether your vehicle has a manual or automatic transmission again the lubricant is tasked with keeping that component both cool and lubricated. Manuals usually only rely on the sump or pan and its inherent volume and design to keep the lubricant cool enough. Automatic transmissions will use a sump plus an external radiator type cooler as they generate a lot more heat.
There is another often forgotten system that relies on the lubricant for cooling. It is especially stressed when you are pulling a trailer. This is the power steering system. These systems use very high fluid pressures to assist with changing the direction your wheels are pointed. This system creates the most heat when your vehicle is at close to rest and you are backing your boat into the lake or your trailer into that tight camping spot. Sawing the wheel back and forth at close to a stop requires peak pressures.
That little power steering reservoir needs to remain full. In many cases power steering systems have external coolers open to the air for cooling.
So most of your vehicle’s lubricants are also acting as coolants.
As such the amounts must be kept at the correct level to ensure they not only lubricate properly but also remain below their design temperature.
When your mechanic is prepping your vehicle for the rigors of a hot summer he/she will be considering all the coolants not just the stuff under the radiator cap.
Trail’s Ron Nutini is a licensed automotive technician and graduate of mechanical engineering from UBC. E-mail: firstname.lastname@example.org