Antifreeze leaves the expansion tank: possible causes and repair tips

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:41

Cars today are no longer a luxury, but only a means of getting around the city or between cities. Any vehicle must be in good technical condition. From time to time there are breakdowns that need to be fixed. In this article, read about the situation when antifreeze leaves the expansion tank. This could be a minor failure, or it could be a symptom of a serious problem, we will consider all possible options.

Radiator

Radiator leak? What to do? The main thing in such a situation is not to panic, because this breakdown is comic in comparison with what could happen. If you find a place where the radiator flows, then you need to analyze everything. Some people solder the hole if it is minor, but this is not a panacea, but a temporary solution to the problem.

Other people pour special compounds into the systems that will clog a hole from the inside, but this is also not quite the right move, because not only a hole inradiator, but all the internal channels of the cooling system will become narrower, and this will reduce the circulation of "coolant" in the system, which can cause more serious problems.

If the antifreeze leaves the expansion tank through the radiator, then you need to change it and forget about the problem. This is the only correct solution in this situation. Prices for original radiators can be biting when it comes to foreign cars, but you can always find a good quality analogue.

Let's say that modern cars have a lot of radiators (main, air conditioning, automatic transmission, and so on), any of these radiators can break down and start leaking, this must be taken into account. It is also important to understand that any of these heatsinks has an analogue that may be more interesting in price than the original version.

Cooling hoses

Another likely problem. Any hose for antifreeze can leak over time. It is desirable to check the cooling system in dry weather and this should be done on the “pit” or on the lift, highlighting yourself with a flashlight. Hard-to-reach places can be probed with a hand, which will definitely feel moisture if there is a leak in any place. In such situations, the cooling system diagram will help, with its help you can view and probe all the lines through which antifreeze circulates.

Expansion tank cap

On some vehicles, the expansion tank cap is equipped with a special valve through which excess pressure in the system is released. Sometimes this valve fails and excess pressure is not relieved. Visually it seems that the level of antifreeze in the tank is decreasing. But if you unscrew the lid, then it is restored. In this case, you need to replace the expansion tank cap with a working one. If this is not done, eventually excessive pressure will lead to a rupture of the radiator, expansion tank or hoses.

Expansion tank

Sometimes there are cracks on it. Especially if it is made of poor quality plastic. It is noteworthy that a crack can form on its reverse side. And it will be imperceptible without completely removing the tank. To find the problem, you just need to remove the tank and carefully examine it for cracks. If cracks are found, the tank must be replaced with a new one, no sealing of cracks is allowed.

Stove

The stove radiator can also leak over time. It is not so difficult to determine this, because in this case there will be a smell of antifreeze in the cabin, and it will be wet under the driver's rug. This problem is not very simple, since it is usually not very convenient to get to the stove radiator, but this will have to be done, since it will need to be changed to a new one. In this situation, you can also buy either the original version, or pick up an analogue.

Pump

This coolant pump has its life. One day, if it is not changed in time, it will leak. The pump for antifreeze should change according to the regulations. Finding a pump leak is not very easy, as it is sometimes located verydeep in the underhood. You need to look for such a breakdown using a flashlight on a raised car on a lift or crawling under a car on a “pit”.

Oil cooler

Some cars have this assembly, and sometimes it can leak over time. In this case, oil will get into the antifreeze, or vice versa. Visually, this will look like the serious problems described below. If the problem is in the oil cooler, then it must be replaced with a new one, and the entire system should be flushed. You can not delay the flushing, because every minute the flushing process becomes more complicated. If it is not possible to flush some part of the system (for example, a radiator), then this place of the system changes to a new one.

Cylinder head gasket

If the antifreeze leaves the expansion tank, and no leak is detected, then this is a reason to start worrying a little. Since the coolant may not go outside, but inside the engine. This is already a serious expensive repair, but there are options that are even more serious and financially costly.

You can identify such a problem by the dipstick of oil (sometimes antifreeze gets into the engine oil in such cases, and on the dipstick it will look like a white emulsion). You may notice a problem in the expansion tank (air bubbles will form in it). Also, this problem can manifest itself through the exhaust pipe (there will be too much white smoke from there while the engine is running). Another symptom is the swelling of the radiator hoses when the engine is running (it is difficult to feel them with your hand during operation due to air being sucked into the system and overestimating the workingpressure in it). In addition, to determine the problem, there is a special gas analyzer that can immediately find out the problem, but in our service stations such a device is rare.

But there are options when the cylinder head gasket is broken, but there are none of the above signs. This may be the case if the gasket is pierced in such a place that the antifreeze does not enter the combustion chamber, but immediately goes into the exhaust system, and white smoke is not visible because, for example, the particulate filter successfully copes with it.

In any case, if a leak is not detected outside, then you need to open the motor and look for the problem already there. Gasketing is just one of the reasons, there are other problems. Read about them below.

Cylinder head

Signs are the same as with the cylinder head gasket, and they may also not be at all. In this scenario, the antifreeze also does not go out, but goes into the engine, but if in the case of a cylinder block gasket it is necessary to remove the cylinder head, replace the gasket and put the cylinder head in place, then in the case of repairing the cylinder head, everything is more serious. If the gasket is in order, then the “cooler” leaves through the “head” itself. So, there is a crack in the "head". This can be determined using special computer equipment. If cracks are found, then they can be tried to weld. If this is not possible, then you will have to change the cylinder head, and on foreign-made cars it can cost several hundred thousand rubles, even a used one.

Old cast iron motors can be lined in these situations, but it's notit will be possible to do it on a modern aluminum engine, unfortunately.

Cylinder block

This is an even more serious alignment. The symptoms are exactly the same as the two problems above. If the gasket and cylinder head are in order, and the antifreeze leaves the expansion tank into the engine, then the cylinder block should already be checked. It also looks for cracks on computer equipment, if they are found, you can try to weld them. If this is not possible, then either the cylinder block or the engine assembly will have to be changed. The costs are more than significant, especially for owners of foreign cars.

How to add antifreeze?

Sometimes when antifreeze or antifreeze goes out, there is no reason to panic. This can happen, for example, once a year during a sharp cold snap. If this happens, then you need to add coolant and observe. If there is no repetition, then forget and relax. If the situation repeats itself soon, then you need to look for where the antifreeze flows from.

It is important to know how to top up the coolant. You need to add exactly the coolant that you have in the system. You can't mix. Topping up is possible only on a cold engine, because if the engine is hot, the coolant can be very hot and under pressure, if you try to top up, you can get very seriously burned.

You need to add liquid within the normal range (there are marks on the expansion tank with a minimum and maximum coolant level, these marks are relevant for an idle cold engine).

Replacement of antifreeze

He must change according to the regulations. Usually this should happen once every two years. This is done because the antifreeze in the cooling system loses its properties over time, and then there may come a time when, for example, radiators begin to oxidize and collapse. This is especially true if they are made of aluminum. For an aluminum engine, this situation is also possible. It is cheaper to change antifreeze than radiators, or than to repair a motor.

Unusual situation

If the coolant is gone on the way, and there is no way to get to the place of repair by tow truck or tow, then you need to act outside the box. You can pour ordinary clean water from a reservoir into the cooling system, but upon arrival home, you need to completely replace the antifreeze in the cooling system. This is especially important if the action takes place in the cold season, when it's cold outside. By diluting antifreeze with water, you reduce its density. When the car cools down, it may freeze. It is for this reason that you need to go to a car service in such a situation in order to leave the car there, and the specialists will drain the antifreeze from it with diluted water, find the cause of the leak, fix it by finding it according to the car’s cooling system diagram, and fill the cooling system with new liquid.

Overheating

When the coolant leaves, the engine starts to warm up. This should not be allowed under any circumstances. Serious overheating will lead to engine jamming, which means that you will have to completely change it to a new power unit. Expensesimpressive, and the initial problem may not be significant. It is for this reason that you should always monitor the level of coolant in the system and its temperature.

Summing up

Antifreeze is not a joke, if its level drops in the system, then this is a reason to be wary. It is impossible to ignore such a problem, it can generally lead to overheating and complete failure of the engine of your car. Sometimes solutions to the problem of a drop in the level of antifreeze in the system are simple and cheap, sometimes they are complex, require significant costs, but in any case, repairs are worth making, because there is simply no other way.