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What Happens When An Engine Cooling System Fails?

engine coolant system serviceExercise is one activity that can quickly warm you up. You begin at a slow pace but as you increase the intensity of your workout your body starts to heat up. Your heart is pumping blood quickly, your face turns red, and you begin to sweat. You may combat the heat by drinking water to help keep you cool and prevent yourself from getting overheated. Just like you, your engine begins at a cool state but as it begins to move, it starts generating lots of heat and like you, needs water to keep it cool. But water is rough on metal engine parts, causing rust and other damage. So coolant, also known as antifreeze, was introduced to help keep the engine water from freezing in winter and with lubricates protect it at the same time. When the cooling system malfunctions it can cause serious and permanent damage to the engine. Find out how your car’s engine cooling system works, why it’s important and what happens when it fails with our answers to common engine cooling system questions.

How Does an Engine Cooling System Work?

The cooling system has multiple components and channels throughout the engine block and heads that are meant to keep the engine cool. These components include:

  • Water pump – to circulate the coolant
  • Thermostat – to regulate the temperature of the coolant 
  • Radiator – to help cool the coolant
  • Radiator cap – to control the pressure of the system and raise the boiling point of the water due to increased pressure
  • Hoses – to move coolant from the engine to the radiator and back as well as to the heating system to warm up the car’s interior when necessary.

The cooling system is a pressurized system controlled by the radiator cap that is made to release pressure as needed. As coolant flows throughout the engine, it attracts heat from the engine. The warm fluid then travels through a rubber hose to the radiator near the front of the vehicle. As it flows through the fins of the radiator, the hot fluid is cooled by the stream of air entering the engine from the car’s grill and the cooling fans. Once cooled, the process begins again by traveling back to the engine to absorb heat. The thermostat, located between the radiator and the engine, ensures the coolant stays below a specific temperature. If the temperature of the coolant falls below a certain temperature, the thermostat closes the passage blocking the flow of coolant to the radiator and sends it back to the engine. Once the temperature returns to the designated temperature, the thermostat will once again open a valve allowing coolant to flow to the radiator. 

What Causes a Car to Overheat?

Most overheating issues are related to some sort of obstacle or failure that prevents coolant from traveling to the radiator to release heat. This issue could be caused by a faulty thermostat, an obstruction in the radiator, a fan or the water pump has malfunctioned preventing the coolant from flowing and dissipating heat as intended. 

How Do I Know if My Car’s Cooling System Has Gone Bad?

When something in the cooling system is amiss, your first clue will be right under your nose. The needle on the temperature gauge will begin to rise with momentum. Your check engine light may illuminate and if you haven’t pulled over at this point and turned off your engine, smoke will begin to escape from under the hood. 

How Does Overheating Damage the Engine?

Overheating is one of the worst things that can happen to your engine. When the needle is rising and the temperature gauge is starting to run hot there are a few simple things you can do to keep your car from overheating. If you’re unsuccessful in preventing overheating you risk damaging the engine permanently. The most common damages to the engine include:

  • Damaged Head Gaskets – Overheating damages seals between the cylinder head and engine.
  • Cracked Engine Block – Overheating may crack an engine block beyond repair or if repairable, result in costly repairs.
  • Burned Pistons – Overheating can burn and melt holes in the tops of the pistons. Reaching the pistons is difficult and requires disassembling the engine to locate them.
  • Seized Up Engine – A loud, thump is the sound of the engine as it shuts down and quits working all together. When this occurs, replacement is often the only solution. 

How Do I Keep My Engine from Overheating?

Coolant is the hero when it comes to preventing your engine from overheating. An engine with no coolant is likely to trigger the check engine light or the temperature gauge, shut down your engine to prevent any damage, or in the likelihood that you continue driving while overheating, severe engine damage. You can prevent overheating in your engine by checking coolant level often (especially in the summer months) and flush coolant every 30,000 miles. 

If you suspect other issues within your cooling system, have a trusted technician perform the following:

  • Look for leaks in the radiator, engine block, water pump, or hoses
  • Inspect radiator fins or cooling fan for blockages
  • Inspect radiator cap and/or seal
  • Inspect water pump and serpentine belt