Car Loosing Coolant? Here’s Why And What to Do

How Long Does Coolant Last?

You want to stay cool during the summer heat but you also want your car’s engine to stay cool. When your car is losing coolant, you can be sure that things are heating up. If you think your car is losing coolant, it’s best to find out for sure. Read on to find out what causes a car to lose coolant, the symptoms to watch for, and what you can do to help the situation if your car does have this problem.

Your Car’s Cooling System

The cooling system in your car is made up of many components which work together to regulate the temperature in and around the engine. There are two aspects to the cooling system, the liquid cooling and the air cooling. Both systems rely on air to some extent, but only one uses liquid. Older automobiles usually have air cooling systems, while some newer models use air. However, most newer models use liquid cooling.

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The liquid cooling system is a bit more sophisticated than the air. The liquid cooling is typical a type of antifreeze composed of ethylene glycol. There are passages in the engine block and also in the heads. A water pump is used to circulate the more high quality coolant (view on Amazon), which is transferred by hoses and cooled in a radiator. There is a thermostat that regulates the coolant temperature. The cap on the radiator controls the pressure within the cooling system.

The coolant travels through the parts of the engine, absorbing the heat. The heated coolant travels through rubber hoses to the radiator. Natural air coming in from the grill cools the coolant as it passes through the radiator. The coolant then returns back to the engine and the process starts all over again.

Causes of Car Losing Coolant

Several things can cause or contribute to a coolant leak. The problem can originate from most anywhere under the hood. Here are the most common causes of coolant leaks in the internal combustion system:

AC Compressor Bearings – The ac compressor is designed to prevent the refrigerant from leaking while it is being pressurized. When the ac compressor becomes worn, the bearings are damaged. The refrigerant is allowed to leak through the bearings. You may see the leak near the compressor. This is sign that your ac compressor bearings have worn out.

Bad Radiator Fan – The environment under your hood is busy and hot. When your car is on the move, natural air presses in through the grill and cools the engines. If the car is idling, or not traveling very fast, there is not enough air to cool the engine. Thus, the radiator fan (view on Amazon), or cooling fan, was designed to blow cool air on the engine to compensate for the lack of air from the environment. The radiator fan also keeps the coolant at a low temperature when it’s hot. When the radiator fan is working properly, cool air is drawn in and blown over the engine.

The air conditioning condenser and the coolant are kept cool. It is much less likely that you will have an overheating problem. If the fan does go bad, it can be associated with many other problems, to include losing coolant. The biggest sign of the fan not working is engine overheat.

Extreme Heat – If temperatures under the hood get hot enough, the coolant will start to evaporate. The engine gets extremely hot and forces the liquid out. When the coolant has air, it does not absorb heat from the engine the same way. These things will likely only happen if your radiator fan is not spinning. Or, it could be the coolant is naturally evaporating over time. However, under normal operating conditions, you should be able to keep the coolant topped off.

Damaged or Loose Radiator Cap – The radiator also keeps the coolant at a low temperature when it is getting hot. When the cap is not on tight, the coolant can escape.

Damaged Thermostat – The thermostat should activate the fan once the engine has reached a certain temperature.

Engine Overheating – – If your car is overheating, it could be because the thermostat and/or the fan is no longer doing the job. When the fan does not come on, the engine continues to heat up until the fan is on or damage occurs. The fan relay could also have failed. Although overheating is not only caused by a bad fan, this is very often the reason and should be investigated first.

Damaged Serpentine Belt – The serpentine belt is an accessory drive belt that affects many parts. When the serpentine belt is cracked or broken massive leaks of coolant can occur under your hood. The power steering and water pumps stop turning. When the belt slips, there can be oil and coolant leaks. . The serpentine belt wears out naturally over time, becomes loose, or it could be damaged in an accident. Once the belt is worn or damaged, it must be replaced.

Blocked Radiator Core or Grill – When the cooling system in your car has not been serviced or flushed in a while, the old fluid sits and accumulates debris or sediment and even rust that blocks the core or grill over time. The cooling fins in the radiator corrode and coolant leaks occur. If the leaks are not addressed in a timely manner, the radiator becomes permanently damaged and must be replaced. It can also cause damage to the head gasket or cylinder head.

Heat from AC during Ambient Temperatures – During those hot summer months the parts under your hood are already working overtime in extreme heat. Your car’s air conditioning system is comprised of several parts which work together to keep you cool in the heat.

Your Treat Your Car Like Shit – Your vehicle’s systems are able to cool down because of the coolant. If you want to make sure that the cooling system is working properly, you need to make sure that the coolant in there is functioning properly. If you’re having to top up your coolant, it’s a sign that there’s a leak somewhere as you should never really have to replace your coolant. If your coolant is leaking, you have failed to maintain your vehicle and now you’re experiencing problems. The main cause linked to low coolant issues is a failure to maintain your vehicle.

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Symptoms of Car Losing Coolant

If your car is losing coolant there are a few tell tale signs. It is extremely important that you look for these signs and find leaking problems early. Here are the most common signs that your car is losing coolant:

Check Engine Light (CEL) – The Check Engine Light (CEL) on your dash will activate to let you know something is wrong. You can use an your professional OBD2 Scanner (view on Amazon) to see if the trouble codes have anything to do with the cooling system.

Coolant on the GroundIf your engine is overheating, it may just mean you need to add more coolant. The leak may accumulate in pools of green fluid under your car. (The coolant can be different colors depending on the manufacturer. If there is coolant on the ground under your vehicle, it could be because it got so hot, the coolant boiled over and spilled from the coolant overflow tank. It can also mean that you have a coolant leak which caused the engine to overheat. If the engine is really hot, the hood will also be very hot. If you cannot touch the hood and let your hand remain for a few lingering seconds, the engine could be overheated.

Sweet OdorWhen there is a coolant leak you will smell a sweet smell coming from under the hood. Actually, you can smell it while you are driving and after you’ve driven. That is the toxic ethylene glycol running through your cooling system. However, you still have to find the leak. When you smell the sweet odor, there are problems that will escalate if you do not fix it.

Temperature Gauge on Hot – if the radiator fan is not working, your temperature gauge maybe rising toward hot. The coolant is no longer being cooled down as it circulates through the engine and the thermostat picks up the change. The temperature gauge on your dash moves toward HOT and remains there until you turn the car OFF.

Blown Head GasketThe head gasket is a type of mechanical seal that is located between the engine block and cylinders which aides in the combustion processes. Evidence of the blown gasket are coolant leaks under the exhaust manifold. If your engine is overheating, the head gasket may be blown.

Smells Hot Under the Hood – Less coolant means your car is very likely overheating. If your vehicle smells hot after you turn it on for a time or you smell it when you get out of it there is a problem with the cooling system. When the engine overheats, the metal, rubber, and plastic components give off a distinctive smell that many describe as “smelling hot”. The smell may also enter the vehicle through the AC vents.

AC air hot – This is another way to tell that your car does not have enough coolant and that there could be a leak. If you turn on your ac and hot air comes out of the vents, there’s something wrong. The air from the AC gets progressively hotter as the AC system works the engine harder and puts a strain on a cooling system that already has a problem.

OBD2 Codes for Coolant Leaks

A way to know if your car has a coolant leak is to use the OBD2 trouble codes. The OBD2 is a state-of-the-art diagnostic computer system that tells you why and when your automobile has trouble. The OBD2 Scanner can read more complex manufacturer codes, shut down the MIL or CEL, and conduct troubleshooting. Some scanners can even set up pids, check on pending codes and generate parameter lists. For your coolant problems, the scanner can really be of help as your car has an Engine Coolant Temperature Sensor (view on Amazon). Here are some common codes for coolant leaking problems:

Error Code P0217 “Engine Overheating Condition” DTC – This code means that the engine coolant temperature sensor has sent a voltage reading to the PCU which is converted to a temperature reading. If the temperature is outside the parameters, a code is thrown and the check engine light is activated. This code means there could be a leak in the radiator, heater housings, thermostat housing, head gasket, radiator hoses, the water pump or even the engine.

Error Code P0480 “Cooling Fan 1 Circuit Malfunction”- This code also lets you know you have a problem in the cooling system. The P0527 “Fan Speed Sensor Circuit” trouble code lets you know there’s trouble with the fan. These trouble codes tell you, if nothing else, that your car needs to be inspected.

Get Help from Certified Professionals

Coolant leaks are no laughing matter, and your car can quickly become expensive in the way of maintenance. Many problems associated with the cooling system cannot be solved with a bit of patching up. Others need a professional eye. Keep your vehicle on the road for the long run, seek certified professional help. Certified technicians know how to replace coolant or service your cooling system the right way.

Job Guthiri is a freelance writer with 3 years of experience writing for Motorsrun and other established automobile outlets. His focus and key interests are Tacomas and maintenance. Read our Editorial Guidlines and Fact Checking process.