Your car's engine and the other components found beneath your hood generate a lot of heat during their operation. To prevent this heat from causing component failure or damaging heat-sensitive materials, all cars contain sophisticated cooling systems. Yet these systems cease to protect your car the minute you turn off the engine.
At that time, all vehicles experience the potentially destructive phenomenon known as heat soak. If you would like to increase your knowledge of this basic yet little-understood part of every vehicle's run-cycle, read on. Here you will learn about what heat soak is, as well as some of the problems it can lead to over time.
As noted above, all automobiles have cooling systems meant to keep your engine and other moving parts within acceptable temperature limits. A special pump sends coolant out from you your radiator through a network of tubes. The coolant absorbs heat in its passage through your system and then returns to the radiator, which passes that heat to the air, thus allowing the cycle to continue.
A well-working cooling system allows your car to run for extended periods of time in even the hottest of weather with little risk of breakdowns or other serious problems. Yet things change the moment you turn your car off. At that point, your engine will remain just as hot as it was during operation, except that your cooling system will no longer be doing anything to control its temperature.
As a result, temperatures beneath a car's hood actually rise in the minutes after a car is turned off. This heat increase is caused by lack of coolant circulation, as well as the sudden lack of airflow. The temperature will gradually cool off, of course, but often not before it has led to serious repercussions for your car.
One area where heat soak can cause problems involves your car's starter. Specifically, the starter may struggle to crank your engine when hot. Cold starts, on the other hand, will present no difficulty. Yet the heat soak that occurs when you turn off a heated engine may be enough to disrupt the proper functioning of the electrical conductors inside of your starter.
Heat affects the conductivity of electricity. The hotter the starter gets, the more electrical resistance it will experience. If this resistance crosses a critical threshold, the starter may fail to crank your car until it has cooled back down to an appropriate temperature. Naturally, you don't always have the time to wait for this to happen.
Corrosion in your battery cables may exacerbate the effects of heat soak. Keeping your battery's terminals and connectors clean will help to reduce the negative effects of heat soak. An even better option involves the installation of a heat shield over the starter. The heat shield reflects heat away from the starter, helping it to resist unwanted temperature increases.
Fuel Injector Problems
Heat soak also tends to cause problems for fuel injectors. As the temperature rises, any fuel left in the injector nozzles will evaporate. This evaporation leaves behind any contaminants found in the fuel. It also leaves behind the waxy olefins that can be found in most gasoline. The excessive heat causes these substances to become baked into the metal of the injector.
In theory, detergents in your gasoline should be capable of removing such deposits before they inhibit fuel injection. Yet for cars that regularly get used for short trips around town, the rate of accumulation caused by heat soak may be more than the detergents can handle. Fuel restrictions will soon occur, along with issues such as misfiring, loss of power, and poor fuel economy.
An experienced mechanic knows how to recognize the signs of excessive heat soak and can reduce many of the problems it causes. For more information, please contact the skilled automotive providers at Broadway Motors Inc.