Air lock in the engine cooling system, how to remove it

The sealed volume of any vessel has a volume limitation. The automotive cooling system should contain only coolant (antifreeze, antifreeze, some use water). Therefore, the presence of air in the cooling system is unacceptable, because it completely stops or disrupts circulation in the system, and you should know how to expel an air lock from the cooling system.

Protection against air lock formation in the cooling system.

An air lock forms in the engine cooling system.

It would seem that the formation of an air lock in the cooling system of an internal combustion engine is such a simple problem, but its presence seriously affects the current and future operation of the engine. Many drivers have encountered such phenomena as boiling antifreeze, antifreeze and water, failure of various sensors, seething - all this indicates that there is air in the system channels, which is stopping circulation. It also happens that after starting the engine the car does not heat up. When the first signs of air appear in the engine cooling system, prompt elimination of the causes is required.

General recommendations

To prevent traffic jams, you need to follow some recommendations:

Timely replacement of coolant. The main warning sign should be untimely replacement of the coolant. It is recommended to change the fluid in the cooling system once every two years. Many drivers do not pay much attention to the cooling system in their car, which is a huge mistake. Irregular fluid changes lead to the accumulation of large amounts of air with each refueling. Gas not only prevents the circulation of substances through the system, but also creates a real risk of engine overheating.

Use high-quality antifreeze. Upgrading doesn't take much time. Regular bleeding will help keep the radiator in good condition for as long as possible. When choosing coolant, give preference to trusted and experienced manufacturers. A high-quality tested product improves system performance and helps in its maintenance.

After the car’s cooling system has been completely pumped, do not forget to add fluid. For optimal system operation, the coolant level should reach the top line visible on the container. It is recommended to add the same liquid that is already in the container. Nowadays, most of the products available on the market have a similar base and can be mixed together without any problems. Always check the manufacturer's recommendations before refueling. The exception is liquids containing propylene glycol, which is green in color. When choosing a coolant composition, the driver should buy those that have a high rating and excellent reviews among buyers. You can minimize the purchase of counterfeits if you buy the product from trusted, licensed stores. Most of the problems in the system arise precisely because of low-grade antifreeze.

Signs of an air lock in the cooling system

You can determine the presence of air in the engine refrigeration system by conducting independent diagnostics and eliminating the causes. We carry out diagnostics based on the above criteria.

Signs:

Checking the system for leaks. Over time, clamps weaken, oxidize, or break completely. The hose also has shock absorption; over time, it bursts and cracks; either heat or cold gradually destroy the rubber.
Problems with the thermostat. If the engine heats up very quickly after starting, that is, the cooling fan has already turned on, and the temperature sensor shows that it is about to push the needle into the red scale, then this indicates a non-working thermostat or the presence of air in the pump discharge pipe. In this case, the thermostat valve will be in the closed position, the coolant will move in a small circle. The opposite may also happen. The engine takes a very long time to warm up after starting. This means that the thermostat valve is fully open or there is an air lock in the thermostat. In all cases, you will have to remove air from the engine cooling system.

It’s easy to check the thermostat yourself; you need to do the following:

start the engine;
after a couple of minutes, touch the radiator pipes (the top one should be warm first, then cold, the bottom one should be cold);
when the engine temperature reaches operating temperature, 80-90 degrees, the thermostat should open and the lower pipe should heat up.

It's also easy to check functionality. It is determined by the noise level (it is not worth using a noise sensor and determining the level in decibels (dB)), by the sound you can already feel how the pump is working. The vibration of the pump is also checked. The pump bearing may have fallen off.

The main clue is that air has appeared in the engine cooling system in the heater. If the engine is hot and the heater is blowing cold air, then there is an air lock.

Why do the cooling system pipes inflate?

Hi all! So who knows, tell me.

The cylinder head gasket is not broken, because it was done, the pipes were swollen, I went to a station, they changed the thermostat, they said it was not working, I drove for 2 days, I touched the pipes, everything was fine, but today I touch them again, they are tight, I turn off the pressure, I reset the pressure, I start it again, everything is fine, BUT the lower one The pipe is always cold even after an hour of driving, and the bottom of the radiator is also icy, the radiator is warm, about 10 centimeters on top, and there is always the same amount of antifreeze in the expansion pipe. The question is what could it be? I changed the radiator cap 3 months ago there are 3 options again the thermostat (broke after 2 days of use))) the radiator is clogged

some pipe is clogged

a day later, the radiator was washed, the lower hose was still cold, I checked the thermostat, it opens, but the thing is that the hoses are still inflating, what could it be? with the radiator cap open you can see the fluid rising up for some reason

So, what exactly is the problem? The pipes should be tight, what is written on your radiator cap? 0.9 or 1.1? This is the maximum pressure in the system, and this is no less. It’s good that I replaced the radiator cap, this should be done periodically, in place of replacing the coolant, once every two years, it is primarily responsible for the pressure in the cooling system.

Or are your pipes inflating like “balloons”? Then just change them, they are reinforced with nylon thread inside and should not swell like balloons. Regarding the thermostat: the lower pipe and radiator are cold, the thermostat is closed, the engine does not reach sufficient temperature to open it. If the engine starts to overheat, i.e. the arrow rises above the middle of the gauge scale, and the radiator is cold, then the thermostat does not open on time, change it.

In my opinion, you are very suspicious, calm down, everything is fine. I don't find any cause for concern in your description. Good luck.

I think they should be tight

Change the pipes if this topic bothers you

tight yes, bloated no. Once I took a new cover (in the summer) and after installing it, all the hoses swelled. I returned the old one to its place, after cleaning it, everything became normal.

but the only thing is that when the car is warm, these pipes cannot be compressed even by a millimeter and the pressure in the system is so high that it happens that the coolant bubbles right up from under the plug and the upper pipe is like boiling water! and the lower icy one is definitely not the norm! After such a trip, a month ago my lower hose fell off and the gasket burned out! done

This happened on an old Honda, the radiator was leaking and the pipes were blowing, we decided to replace the radiator, it was also clogged. The previous owner ruined it with sealant. Another option for inflating the pipes could be the radiator cap - the valve had died.

You can check the gasket easily - lower the hose from the expansion tank into a bottle of water, warm up the engine and rev it up normally, if the gasket is bad, you will see bubbles.

It’s not sad, but it looks like a cylinder head gasket

Express method (inaccurate) - remove the radiator cap and smell the coolant - if it smells of gasoline or exhaust, then that's it - the gasket

You can also taste the condensate from the pipe (if you are not squeamish). Fresh water is ok, sweet water is definitely a gasket.

You're talking about horror stories here. )))) and this option: the machine is completely warmed up. Are the lower and upper pipes hot but soft? whats up?

When the cylinder head gasket is damaged, as a rule, 3 scenarios are possible: 1. Antifreeze gets into the oil as a result of its foaming and, as a result, the engine wedges - in the absence of attention to the problem. 2. Antifreeze enters directly into the combustion chamber - white smoke (steam) even in the summer behind the car. 3. Exhaust gases enter the engine cooling jacket because

the pressure of the latter is greater than the coolant pressure, the coolant is forced out of the radiator into the expansion tank, airing the cooling system, and possible overheating of the engine. In your case, it seems to me, two options are possible: 1. The radiator is clogged, whether your car has mileage in the Russian Federation or not, perhaps the previous owner (dabbled) with radiator sealants. 2. Well, in any case, your radiator cap is faulty, which serves as a valve for releasing excess pressure (liquid) into the expansion tank.

Try draining the coolant from the radiator, disconnecting the pipes and checking its permeability at least using a pump. If in this case everything is working properly, check the system for permeability.

Reasons why air appears in the cooling system

Air appears in the system due to malfunctions, actions or inactions on the part of the driver. The following reasons are identified:

The tightness of the system is broken. This could be a loose clamp, fitting, or cracks in the hoses.
Work has been carried out to replace or top up the coolant. This is, as a rule, the most common reason for air getting in, because not everyone knows that it should be poured in a thin stream. If you pour in a thick stream, a funnel is formed that swirls the air.
The air valve is out of working order. This valve is located in the coolant reservoir cap. During natural heating or by installing and starting an autonomous engine preheater, the volume of liquid increases, the pressure in the tank increases and excess air must be discharged through the valve in the lid. This is also a common reason. This is the first place to look for the reasons for airing in the cooling channels. This cover costs 100 rubles for modern VAZ cars. Whoever changes it, when he has already double-checked all the reasons, even after replacing the cylinder head, it turned out that the reason was precisely the non-working cover.
Problems with the pump (pump). The seals and fibers in the pump may be faulty, causing air leaks.
There is a leak through a bolt in the cooling radiator (not available on all models). If there is a leak of antifreeze, antifreeze or water, the lost volume is filled with air.
Burnt cylinder head gasket. If the engine has already been overheated, then there is a possibility that the cylinder head gasket has burned out. When it burns, coolant is released either into the crankcase or into the exhaust system. Seething and boiling begins when the volume of coolant (coolant) has decreased and the entire void is filled with air. In this case, repairs and replacement of the head gasket will be required; for this you need to know what types of cylinder head gaskets there are.

If coolant gets into the engine crankcase, it is easy to check with the oil level dipstick; the level will be higher than expected. If water is used as coolant, the engine oil will turn white. Sometimes air gets into the brake system, in which case the system also needs to bleed air. And for this you need to know the diagram, which wheel to start with and what exactly to do to bleed brakes with ABS and how to bleed brakes without ABS. If the entire fuel fluid has leaked or you want to replace it, then such work also has its own nuances. In particular, you need to know which brake fluids can be mixed and how much brake fluid is needed for replacement.

How to expel air correctly

According to experts, the process of removing air is quite easy and simple. To complete the procedure, you only need to spend fifteen minutes. When you contact a car repair service, you will need to pay a considerable amount of money. Therefore, it is better to carefully listen to the advice of specialists and carry out the steps yourself in a matter of minutes.

So, after moving the clamp, air will escape. During the operation, you can hear a pinching sound. As soon as the air lock is removed, cooling antifreeze will flow from the tubes. This action is characterized by the release of air. Accordingly, you can return the clamp to its place. During the work, it is also necessary to check the functionality of the entire cooling system to avoid leaks.

By tightening the clamp tightly, you can add cooling antifreeze. The amount of liquid should reach the max. As soon as antifreeze is added to the expansion tank, the heater should be diagnosed. With normal air circulation and warm flow, we can assume that the work is 100% complete.

How to remove air from the engine cooling system

The process of removing an air lock on cars is almost the same, be it Kalina, Priora, Granta, Hray, Vesta, VAZ 211(0-5), 2101-2107, Opel, Daewoo Matiz, Nexia, Nissan Almera, Gazelle Business, Audi 80-100 , BMW E39, Peugeot, Chevrolet Cruze, Skoda, Mazda, Mitsubishi Lancer, Suzuki Grand Vitara, Niva, UAZ, Volkswagen, Ford, Renault Duster, on Chinese Lifan and even on premium class cars.

There are several options for removing an air lock from the cooling system:

Option #1:

Remove the plastic casing from the internal combustion engine. Why do you need to unscrew the filler cap to fill the oil? Remove the trim. After removing the casing, you need to close the neck to avoid the ingress of various kinds of objects.
Find the pipes that provide heating for the throttle assembly.
Remove any one pipe.
Unscrew the cap of the expansion tank.
Cover the neck with a clean piece of rag or tightly connect the hose and blow into it.

Thanks to this method, air and the general system are bleed. You need to blow until liquid flows out of the disconnected pipe. Then, immediately put the hose back in place.

Option #2:

Start the engine and let it run for about 15 minutes.
Turn off the engine.
Disconnect any pipe on the throttle assembly.
We do not touch the tank lid; it must be closed.
Wait until the coolant starts to flow out.
Place the pipe in place and tighten it tightly with a clamp.

To use this option, it is advisable to wear thick rubber gloves and overalls, because the temperature of the liquid is about 90 degrees.

Option #3:

Place the car on a steep incline with the front end facing up (the steeper the better).
Set the handbrake.
Place wheel chocks (chocks) under the wheels.
Unscrew the plugs from the expansion tank and the cooling radiator.
The car should run for about 15 minutes with this setting.
The antifreeze will gradually descend into the system, and the air will escape.
Add antifreeze and gas.
When the bubbles end, all the air has escaped.

How to properly prepare for work

Before you begin bleeding air, you must consider the following rules. First of all, you should find a place with a flat surface to park your car. This will ensure ease and comfort during the repair work.

Therefore, in order to completely bleed air from the engine cooling system, you should acquire special tools. You will need to purchase a pair of keys and a Phillips screwdriver to easily remove the clamp.

It is important to note that you can begin repair work literally ten minutes after your car has cooled down. It should also be noted that the engine should not be running when you begin to carry out the actions. After all safety standards and regulations have been taken into account, you can climb under the hood and remove the expansion tank cap. Then you will have to loosen the clamp. Through this tool, coolant is supplied to the unit.

A specialist can check the gases, excess pressure, and fluid levels in the cooling system. But for this work, the mechanic will charge you a lot of money. Therefore, we suggest you do the work yourself with the help of our valuable advice.

When performing repair work, it is necessary to monitor the process to avoid unnecessary damage. For example, you should work carefully with the pipe. Next, you can freely remove the air plug.

Protection against air lock formation in the cooling system

In all matters related to malfunctions and subsequent repairs, the easiest way is to prevent the occurrence of breakdowns; in this case, it is necessary to prevent the appearance of an air lock. It is advisable to learn how to fix simple breakdowns and perform preventive maintenance yourself, then you won’t have to contact a car service center.

One of the main preventive measures for the formation of an air lock is not to bring the coolant to a boil (do not overheat the engine). If antifreeze is poured in, it can withstand higher temperatures than antifreeze, and even more so than water. When the coolant boils, steam is formed, which is pressed into the most inaccessible corners of the ignition system. In such cases, certain types of breakdowns appear.

Author of the publication

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Minimal air ingress during coolant replacement process

Replacing an air item without getting air in is really easy. To avoid unnecessary problems, you need to disconnect the coolant supply hose from the fitting. This procedure is mainly carried out by owners of injection cars. If the engine is dominated by a carburetor, then the coolant supply hose should be disconnected from the carburetor fitting.

In this case, it is necessary to fill the unit with coolant to the max. level. Then you will have to close the lid tightly. You should not forget about connecting hoses that were removed during the work.

In this way, gases, oils and other compounds will no longer be heated. It doesn't really matter whether it's a gas or gasoline engine. The main thing is to correctly follow the steps indicated in this article.

It would seem that what could be dangerous if a little air gets into the cooling system? In fact, an air lock formed in the cooling system can cause severe overheating and, as a result, engine failure. In addition, the resulting air lock interferes with the operation of the heater. Removing an air lock from the cooling system is a simple procedure; doing this is much easier than later eliminating the consequences of engine overheating.

Malfunction prevention

Instead of eliminating the problem, it is easier to take measures to prevent it. The main rule for protecting the cooling system from outside air is timely diagnosis. The system must be checked regularly for leaks. To prevent air locks from appearing in the future, you should adhere to the following rules:

Do not allow the engine to overheat or the liquid to boil. The coolant turns into steam, which, under pressure, penetrates into hard-to-reach corners of the cooling system. He is not able to leave them on his own.
Regularly flush the cooling system with water or special fluids. Some drivers advise doing this with Coca-Cola or Sprite drinks. A clean radiator works correctly, so plugs do not form in it.
Correctly fill coolant. Before adding fluid, loosen the clamp and disconnect the fluid supply hose in a car with an injector. In a carburetor engine, disconnect the fluid supply hose from the carburetor fitting. Coolant is poured into the tank to the maximum level. Do this slowly and in a thin stream so that the air from the tank is replaced by water. If there is no level mark, liquid is poured to the top edge of the tank. The filled tank is closed when air bubbles disappear on the surface, then the hoses are connected. After these steps, start the engine and warm it up to operating temperature. After turning on the fan, turn off the engine and check the coolant level. If necessary, add coolant.

Proper coolant changes reduce the risk of air in the system

It is important! The use of high-quality coolant is one of the conditions for preventing air locks. Experienced drivers also advise installing a special filter, which allows you to use even low-quality fluids, but you will have to change it every 3-5 thousand kilometers. Therefore, it is actually more profitable to purchase high-quality liquid.

It is necessary to remove the air lock at the first signs of its appearance in the cooling system. Ignoring the malfunction will lead to expensive vehicle repairs or complete loss of the engine.

Author: Andrey
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Useful tips

To avoid problems with the engine cooling system during operation, as well as to extend the life of the components (pump, thermostat), you cannot use ordinary water instead of antifreeze or antifreeze. It is also not recommended to use distilled water instead of antifreeze. This water should only be used to dilute antifreeze or antifreeze concentrate in the required proportion.

In this case, frequent addition of only distilled water to maintain the level leads to the fact that the density of the solution decreases. This can lead to freezing of coolant in the system in winter. To prevent this from happening, you need to check the density with a hydrometer. If necessary, the density is adjusted by pouring undiluted concentrate.

As a rule, the service life of antifreeze is 2-3 years (depending on the manufacturer, quality of the composition, engine condition, etc.). For example, the ingress of gases from the combustion chamber into the cooling system, severe overheating of the engine, general contamination of the cooling system, the use of special sealants for the “stop-leak” cooling system and other nuances can quickly render fresh coolant unusable.

The car radiator also needs to be periodically washed not only outside, but also inside. This will get rid of rust, scale, decay products of antifreeze or antifreeze, etc. The result is maximum performance of the cooling system, which eliminates engine overheating even in the most difficult conditions, as well as efficient operation of the stove in winter.

Checking the car cooling system pump. Main symptoms of malfunctions. Diagnostics of the water pump without removal, troubleshooting with removal from the engine.

How often does antifreeze need to be replaced? Self-cleaning of the cooling system from dirt, scale and rust. Products for flushing the internal combustion engine cooling system.

The principle of operation of sealant for the engine cooling system. When to use sealant, what results to expect. Possible consequences, advice.

Reasons why coolant starts to leak. How to find the location of an antifreeze or antifreeze leak yourself. Useful tips and tricks.

Do-it-yourself flushing of the engine cooling system radiator. How and what is the best way to flush the radiator from the inside without removing it from the car. Recommendations.

Rust in the engine cooling system and engine: what to do and how to remove contaminants. Affordable methods for cleaning the cooling system with your own hands.

Stopper removal methods

Before removing the plug, the cause of air getting into the cooling system is eliminated. If the cause is not eliminated, the removed air will reappear in a fairly short period. After eliminating the problem, you can begin to remove the plug.

The first step is to eliminate the cause of the airlock.

The vehicle is placed on a slope so that the radiator neck is at the top. This position will facilitate the release of air from the system. But simply lifting the radiator neck is not always effective, since the closed cycle of the cooling system does not allow the air lock to move on its own. To facilitate the release of air, the following methods are taken:

Depressurization of the system. The motor is turned on for 10 minutes. Then they muffle and loosen the connections at the radiator outlet pipe. The tank lid is left in place. Wait for the liquid to start flowing out and return the pipe to its place.
Mechanical blowing. Remove the casing and cover, pull off one of the pipes intended for heating the throttle assembly. Remove the lid of the tank, place a rag on the neck and blow into it. This action creates pressure within the system, pushing air out. Coolant flowing from the pipe indicates that the plug has been removed. As soon as this happens, the pipe is returned to its place as quickly as possible, and the removed parts are installed. Delay in action is unacceptable, because air can get inside again.
Expulsion of air by liquid. Antifreeze (antifreeze) is poured into the expansion tank up to the top mark. Then unscrew the radiator cap, start the engine and turn on the heater. You must wait until the stove starts working at maximum power. At this moment, the thermostat starts working and the damper opens to its maximum value. You need to wait until clean, bubble-free coolant flows out of the hole. The hole can be closed and antifreeze (antifreeze) added to the expander to the operating level.

It is important! The main element of the cooling system is the thermostat. Its serviceability should be given special attention. If the device is broken, then simply getting rid of the air will not help.

After using any method of removing an air lock, it is important to check the operation of the stove and compliance with the correct temperature conditions of the engine.

Video: how to remove an air lock

Video: Lada Kalina. We expel the airlock.

Causes of traffic jams

An air lock appears in the system for the following reasons:

Depressurization of pipes, fittings, tubes. Air is drawn in through the cracks of the damaged area due to depressurization and the resulting decrease in pressure.
Air ingress when adding or replacing coolant.
Loss of water pump seal due to worn seal gaskets or cylinder head gasket. Liquid leaks through the damaged area.
Tank valve sticking. Instead of releasing excess pressure, the valve works to pump in air.
Use of low-quality antifreeze. It boils even with minimal engine overheating. A good antifreeze maintains temperatures up to 150 degrees without steam formation. Cheap fakes boil at 100 degrees.

Prevention of air pollution causing engine overheating

To eliminate cooling problems, you need to follow the recommendations:

periodically check the antifreeze level;
use only tested coolant (coolant);
when replacing, it is recommended to pay attention to the color of the coolant and buy a similar new one;
problems that arise must be eliminated immediately after they appear, without waiting for the situation to worsen.

The main recommendation of experts is to carry out maintenance by trusted technicians and not to pour water into the system.

How to check the cooling system pump?

By checking the pump without removing it from the engine, we can only indirectly assess its performance. When the volume of pumped coolant decreases, the stove begins to heat poorly. But before removing the water pump to inspect the impeller, we recommend checking the thermostat and also making sure that there is no air lock in the cooling system.

After removal, pay attention not only to the integrity of the blades and where the impeller fits on the drive shaft, but also to the shape of the blades. For example, on the VAZ 2121 over many years of production, impellers were installed that differed in the diameter of the pump wheel, the number and profile of the blades. Installing a less efficient pump on a more heat-loaded engine modification will result in the cooling system fan turning on more frequently and an increased risk of overheating.

Be sure to inspect the engine block where the housing fits and the pump itself. Fogging or a slight leak of coolant from the drain hole does not mean that the pump should be replaced. If a significant leak is detected, try to pinpoint the location of the leak. If the leak is only at the junction of the housing and the engine block, most likely the problem can be eliminated without replacing the pump. It will be enough to apply sealant and install a new gasket.

Risk of timing belt breakage

The danger with a misaligned water pump timing belt is that there are no obvious signs of failure. First of all, you need to pay attention to the timing belt. If it is pulled to any side, uneven production is observed, it is necessary to check the pump and rollers. The cause of the misalignment may be a manufacturing defect, bearing wear, or uneven fit of the housing to the engine block (dirty, rusty mating planes). Sometimes the malfunction begins to manifest itself after an accident, when elements of the body or attachments hit the pump pulley.

If a misalignment is detected, the defective pump must be replaced as quickly as possible. Also, do not hesitate to eliminate noise and whistling from the water pump. If wear is critical, the bearing may collapse, thereby blocking the toothed pulley. A jammed pump is guaranteed to lead to a broken timing belt. If on your car the pistons meet the valves when they break, then eliminating the consequences of the malfunction will cost a fairly large sum.

Bearing check

The easiest way to check is a pump whose pulley is in an accessible place and is rotated by a drive belt. It is enough to grab the pulley with your hand and shake it in different directions (video check). If there is a malfunction, you will feel a lot of play. To determine that the noise or whistle when the engine is running comes specifically from the cooling system pump, remove the drive belt and unscrew the pulley by hand. A worn bearing with washed out lubricant will rotate with noticeable noise and rolling motions.

Damage from airing the cooling system

The main problem with engine overheating, if ignored, is that it can completely destroy the engine. In particularly advanced cases, it may turn out that it is cheaper to replace the engine completely than to fix problems in every broken part (if most of the elements are damaged).

Among the problems that will arise “here and now” if the cooling system is not ventilated, we can highlight:

Incorrect operation of sensors. They incorrectly display the temperature not only to the driver, but also to other vehicle systems.
Malfunction of the thermostat, which can become an additional reason for engine overheating.
Low temperature of the interior heating furnace. This leads to severe fogging of the windows, which reduces visibility of the road and leads to increased risks when driving.