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Engine Cooling System Repair

The last thing you want for your engine is for it to overheat. Overheating can cause the metal of the system to swell, warp and even crack, breaking the engine and its components. Call 12th Street Auto Care Center today for all engine-related maintenance, services and repairs.

ASE and AAA Approved Engine Cooling System Technicians

Our expert ASE-certified mechanics and cooling system technicians are happy inspect, repair and maintain your engine’s life. One of the best ways to keep your vehicle’s engine running is by ensuring the cooling system is maintained. The cooling system is responsible for keeping the engine nice and cool so it doesn’t overheat. Sometimes, special equipment is required to service the engine’s cooling system, so it isn’t something just anyone can do. Thankfully, 12th Street Auto Care Center owns those specialized tools. Call us today to set up a maintenance appointment at our vehicle repair shop.

auto cooling system repair Sioux Falls, SD auto mechanic

Engine Cooling System Components

To keep your engine cool enough to avoid overheating, but warm enough to run efficiently and cleanly, it relies on a cooling system. The system pumps a chemical liquid mixed with water through the engine and around a circuit of hoses and pipes to maintain a balanced temperature under your hood. The liquid is antifreeze, also known as coolant, which consists mostly of ethylene glycol or sometimes propylene glycol. Coolant has an appropriate name, since it cools and stabilizes the engine’s temperature and can last about three years. But how does the coolant move throughout your engine? It needs a water pump.

Engine Water Pump

The water pump, also known as a coolant pump, is a basic centrifugal pump that circulates coolant throughout the engine block while the engine is running. The water pump is the heart of the engine cooling system. It is driven by the engine drive belt via a pulley system, which is connected to the crankshaft. When the engine first starts up and the coolant is circulating through, it does not continue through the whole system until the thermostat tells it to circulate.

Car Thermostat

After passing through the engine block, the coolant reaches the car’s thermostat. In newer vehicles, the thermostat is controlled by a micro processor. When the antifreeze reaches the thermostat, the coolant is either looped back to the water pump to cycle through the engine block and back to the thermostat, or, if the coolant is hot enough, the microprocessor sends a signal to a valve that opens, allowing coolant into the radiator to be cooled. Once the antifreeze is properly cooled, it is recirculated throughout the engine to pull heat from the components.


After passing through the thermostat, the coolant flows through a hose and into the radiator. The coolant will then travel through the core tubes of the radiator to cool off. Due to the radiator’s aluminum design, the heat is conducted through the wide surface area of the radiator’s cooling fins and is then transferred to the air that flows through the radiator.

The radiator fan helps control the air flow and the cooling process. The radiator cap allows the buildup of pressure in the radiator and increases the coolant’s boiling point. Should the pressure become too much, the radiator pressure cap allows the coolant to overflow into the radiator overflow tank, or coolant reservoir. Once the coolant has released enough heat, it is recycled back into the engine cooling system.

Coolant Reservoir

Overflow from the radiator travels through a hose into the radiator overflow tank, or coolant reservoir. Because the design of the radiator pressure cap works in conjunction with the overflow tank, the engine cooling system remains a closed cooling system that doesn’t allow air to enter. The collected coolant overflow eventually cools and is returned to the water pump before rejoining the cooling cycle. It does this via vacuum created by the decreased temperatures within the cooling system. But the radiator isn’t the only way your engine stays cool.

Heater Core

Much like a radiator, the heater core pulls heat from the coolant. This process happens with help from a fan, and it releases the heat into the vehicle’s cabin. Once stripped of its heat, the coolant flows back into the water pump to rejoin the engine cooling system’s circuit.


Coolant, or antifreeze, is the most integral part of the engine cooling system. Without it, the engine would overheat or freeze. Antifreeze, is a mixture of ethylene glycol and water, or sometimes propylene glycol and water. Liquid coolant can absorb heat from the engine as the antifreeze passes through the water jackets within the engine cooling block. It then travels back to the water pump, radiator or to the heater core, which pulls heat from your engine.

Coolant can last three years or longer, depending on the kind of coolant you purchased: Inorganic Acid Technology (IAT), Organic Acid Technology (OAT) or Hybrid Organic Acid Technology (HOAT). It is crucial to change your antifreeze and check its consistency regularly. Unchecked antifreeze can cause serious damage to your vehicle’s engine. If it’s been a while since your last inspection, call 12th Street Auto Care Center to schedule an appointment and for a free estimate.

Ways to Maintain Your Engine Cooling System

12th Street Auto Care Center’s expert mechanics are happy to service your vehicle and all of its engine cooling system issues. We have special equipment that helps us diagnose any problems your cooling system may be experiencing.

The best way to maintain your cooling system is to bring your vehicle in to 12th Street Auto Care Center at least once a year.

Signs the Engine Cooling System Needs Repair

There are a few ways you can tell when your cooling system needs to be repaired. Many symptoms are visible. Here are the major signs indicating there is a problem with your cooling system.

  • Engine overheating
  • Smoke under the hood
  • Internal fluid leak
  • External fluid leak

Signs My Coolant Needs Replacing

After years of use, coolant can lose its potency. Antifreeze usually lasts three to seven years. There are factors that can affect the longevity of your coolant, so in general you should inspect it annually.

Not sure what to look for? Here are a few signs indicating the coolant might need to be replaced.

  • Clear color
  • Free of grime and no floating chunks
  • No rust or sludge

There are other tests that can tell you whether your coolant is still good, but these are best taken at 12th Street Auto Care Center. These methods include using a coolant hydrometer, multi-meter or voltmeter, and pH tests.

Replacing Old Coolant

If your coolant needs replacing, or you want to try a different kind of antifreeze, 12th Street Auto Care Center can clean your engine cooling system before filling it up with fresh coolant. We have a special machine that flushes all the components that clears out sludge, rust and grime. Once your cooling system has been cleared, it is ready to be refilled.

Call 12th Street Auto Care Center today to schedule a coolant flush and refill. Not sure your vehicle is ready for that? Our ASE-certified technicians will inspect the antifreeze and let you know what it needs.

Napa Service Assistant

You don’t have to be an expert to know that preventive maintenance is the best way to make sure your vehicle is running properly. Use our interactive vehicle tool to learn about the maintenance and services your NAPA AutoCare Center can provide.

Napa Interactive Maintenance Tool