Four Symptoms Of A Sick Cooling System

Four Symptoms Of A Sick Cooling System


Knowing the symptoms of a sick cooling system are critical to reduce your chance of an unwanted breakdown. The most noticeable symptoms of a sick cooling system are overheatingleaks, a sweet smell of antifreeze and repeatedly needing to add coolant.

“Neglecting your cooling system can result in serious damage and even complete engine failure, which would put a sudden end to your summer road trip,” said Rich White, executive director, Car Care Council. “If the cooling system doesn’t receive regular maintenance, it’s not a question of whether it will fail, but rather when it will fail. Performing regular checkups of belts, hoses, the water pump and fluids will ensure your car remains properly cooled and healthy for many miles down the road.”

The primary job of an engine’s cooling system is to remove the heat that is generated during the combustion process. A vehicle’s coolant temperature can be well over 200 degrees and that heat must go somewhere, otherwise engine components are going to fail. The key parts of the cooling system that remove heat from the engine and automatic transmission are the water pump, radiator and thermostat. The water pump circulates coolant through the engine. The coolant absorbs heat and returns it to the radiator where heat is dissipated. The thermostat regulates the coolant temperature to keep it consistent for efficient engine operation.
  1. Overheating: An engine will often overheat when coolant is no longer circulating through the engine. Loss of circulation may commonly be caused by a coolant leak or a failed water pump or thermostat. If you are experiencing an overheating problem, then remember to never check Coolant levels while engine is Hot. Once the engine has cooled, then you can remove the radiator cap to determine if the coolant level is low. If coolant is low, then first check for leaks in hoses. If a leak is difficult to find, then you may opt to have a service center pressurize the cooling system to locate a coolant leak. Continuing to drive an overheating engine can quickly cause complete engine failure. Should you choose to add coolant to a system, then please remember to properly determine the coolant type. Mixing different types of coolant can cause gelling and possibly clog the radiator.
  2. Leaks:  Motorists can do a visual inspection of hoses, belts, thermostat, freeze plugs, fan blades and the radiator (including the pressure cap) to help identify cooling system problems before they escalate. Radiator leaks, bulging hoses or frayed and cracked belts are clues that the cooling system needs maintenance. Leaks in the cooling system can happen anywhere so do a thorough inspection if you suspect a leak. These can be an easy fix.
  3. Smell: The smell of antifreeze when it is hot smells like sweet syrup. The smell is sweet but unmistakable. This could mean a major problem for your cooling system. Again, there could be a leak or you could just be burning through coolant. This could mean a problem with your head gasket. An easy way to verify a head gasket leak is if you have white exhaust. White exhaust means that you are burning engine coolant in the combustion chamber of the engine. If this is happening you should stop driving the vehicle as further use will damage the internal working of the engine.
  4. Low coolant level:  Any number of causes can reduce the coolant levels in your car;
Overflow Reservoir: Most overflow reservoirs come equipped with a small tube that allows the coolant to escape if the engine gets hot enough and the coolant expands past the full mark on the overflow reservoir. This can happen on hot days when you also run your air conditioner. Because of this, you need to check the reservoir level periodically to ensure coolant is between the minimum and maximum marks on the reservoir. Use the recommended mix of coolant and water for your vehicle.

Radiator Leaks: Small pinhole leaks in the radiator will cause coolant fluids level to drop. Pinhole leaks may not be noticeable during operation, as the fluid will leak when the car is running under load. But after operation, the radiator will give off a hot moist smell and show signs of leaking underneath. Pinhole leaks will grow if not fixed. Replace the radiator or have it repaired at a radiator repair shop.

Leaking or Blown Head Gasket: A leaking or blown head gasket will cause water to leak into the areas of the block where it was not designed to go. This will cause the coolant fluid levels to drop without any noticeable leaks under the coolant reservoir, hoses or radiator. Another way to check for a faulty head gasket is to check the oil dipstick. Look at the color of the oil at the end of the dipstick. If it's milky in appearance, or water bubbles appear, this is a good indication of a blown head gasket.

Hoses and Connections: Check all connections where hoses connect to the radiator and the engine. Make note if you see any fluid around these areas. Bad hoses may not show leaks until the engine is on. Replace any hose clamps or bad hoses. Include radiator hose inspection during oil changes or tuneups to prevent problems with the cooling system in the future.

Radiator Cap: A malfunctioning radiator cap can be the cause of fluid leaks in the coolant system. Never take a radiator cap off after the car was just shut off, as the system is under pressure. Wait until the radiator is cool to the touch before removing the cap. Replaceable caps are available from auto part stores for a small price.

You should also check the cooling system for electrolysis. This occurs when an electrical component is not properly grounded and routes itself through the cooling system in search of one. Likely sources are electrical accessories that are bolted to the engine and components in the cooling system, such as the starter motor or engine block to the battery ground connection. The destructive effort of electrolysis may be in the form of recurring pinholes in the coolant tubes of the heater and radiator core or where mounting brackets are attached.

Additional signs of cooling system problems include the vehicle temperature gauge rising near the danger zone, coolant leaks, steam or hissing sounds under the hood or the district smell of an engine that’s running hot.

Proper Maintenance

A major factor that affects the replacement of cooling system parts is the frequency of regular maintenance, such as coolant changes. Motorists should consult their owner’s manual for specific recommendations about how often to change antifreeze and flush the coolant system. A coolant flush and fill is basic to cooling system maintenance as new antifreeze helps the engine run cooler and a flush removes dirt or sediment that could damage other cooling system parts such as the heater core.

The coolant level should be checked regularly at the reservoir and motorists are reminded to NEVER open a hot radiator cap. If the coolant is low, a 50/50 mix of approved antifreeze and distilled water should be added.

We recommend testing your coolant and brake at each oil change to closely monitor when the best time is to have your fluids changed.


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