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Zylinderkopfdichtung kaputt! Trotzdem fahren?
Eine defekte Zylinderkopfdichtung mag auf den ersten Blick wie ein kleines Problem wirken – ein wenig Rauch hier, etwas Kühlmittelverlust
Druck im Kühlsystem – Ursachen, Anzeichen und Lösungen
Your vehicle's cooling system is one of the most important components that ensures smooth engine operation. Its task is to keep the engine at an optimum operating temperature by dissipating the heat generated. However, it can sometimes happen that the pressure in the cooling system is too high. This phenomenon often indicates an underlying problem that you should not ignore.
Table of contents
Table of contents
Beware of excessive pressure in the cooling system! Quick action is now required!
Increased pressure can have far-reaching consequences, from reduced engine performance to serious damage resulting in expensive repairs. But don't worry! With the right information, you can identify the causes, understand the symptoms and take action to solve the problem.
What causes increased pressure in the cooling system?
There are a number of possible reasons why the pressure in your car's cooling system is rising. Some of these are easy to fix, while others require a more in-depth diagnosis. Here are the most common causes in detail:
1. defective cylinder head gasket
One Damaged cylinder head gasket is one of the main causes of increased pressure. Why? The cylinder-head gasket ensures that the combustion chambers of the engine remain separated from the cooling system ducts. If it leaks, combustion gases can enter the cooling system. This not only leads to an increase in pressure, but also to the formation of bubbles in the coolant. Such a defect is critical and should be rectified immediately, as in the worst case it can lead to engine damage.
2. air in the cooling system
Air in the cooling system may sound harmless at first, but it can cause massive problems. Air bubbles disrupt the flow of coolant, causing the pressure to be distributed unevenly. This often occurs after improper filling of the cooling system or due to small leaks through which air can enter. If air remains trapped, the function of the entire system is impaired and the engine can overheat.
3. defective radiator cap
The radiator cap may be an inconspicuous component, but it has a crucial task: it regulates the pressure in the cooling system. If the cap no longer seals properly or the built-in pressure valve mechanism fails, this can lead to excess pressure. A defective radiator cap is therefore one of the first things you should check.
4. clogged radiator or thermostat
Over time, deposits or dirt particles can accumulate in the radiator or thermostat. These blockages obstruct the coolant flow and cause the pressure in the system to rise. A jammed thermostat that no longer opens or closes correctly can also be the cause.
Fast repair
with Steel Seal®
At Steel Seal®, we offer a quick and cost-effective solution for repairing defective cylinder-head gaskets and leaking cylinder heads without dismantling or disassembly. Thanks to a unique thermochemical formula, Steel Seal® precisely seals hairline cracks in the engine from the inside out and permanently restores the function of the cylinder-head gasket.
What symptoms indicate that the pressure is too high?
Bubble formation in the coolant tank
The formation of bubbles in the coolant reservoir is one of the clearest warning signs that something is wrong with your cooling system. Normally, the coolant in the system circulates smoothly and evenly, so there should be no visible bubbles. However, if you notice persistent 'bubbling' or fizzing when you open the expansion tank, this is a clear sign that air or - worse still - combustion gases have entered the cooling system.
These bubbles are often caused by a defective cylinder-head gasket. The cylinder-head gasket ensures that the combustion gases remain in the engine compartment and do not enter the cooling circuit. However, if it is damaged, the high-pressure gases can escape from the combustion chambers into the cooling system. The result: small bubbles that travel through the coolant and cause a permanent effervescence. Such gases can significantly increase the pressure in the cooling system, which can lead to further problems such as overheating or bloated hoses.
Another indication of a defective cylinder-head gasket in conjunction with blistering is rapid contamination of the coolant. If you notice a dark or oily discoloration, this is an indication that Engine oil or combustion residues in the coolant have arrived.
Inflated or hardened radiator hoses
Radiator hoses are the lifeblood of your cooling system, as they transport the coolant between the various components such as the engine block, radiator and expansion tank. If these hoses are overstressed by excessive pressure in the system, they can expand and inflate.
A blown radiator hose occurs when the pressure becomes so high that the material reaches its load limit. As a rule, such a hose also hardens. The rubber loses its elasticity and feels stiff or unyielding to the touch. This is a clear warning signal: the hose could tear or burst at any time, causing the entire cooling system to fail and your engine to overheat in no time at all.
Minor damage such as micro-cracks can also occur if the hoses are swollen and leaking coolant. Therefore, check the condition of your radiator hoses regularly - especially if your vehicle is older. If you discover a swollen or hardened hose, it is essential to replace it immediately to avoid expensive consequential damage.
Motor overheating
One Motor overheating is one of the most dangerous symptoms of excessive pressure in the cooling system. The pressure impairs the circulation of the coolant, either because air bubbles disrupt the flow, the thermostat is jammed or the radiator is no longer working optimally. If the coolant can no longer cool the engine sufficiently, its temperature rises rapidly.
Signs of overheating can be a rising temperature display on the dashboard while driving or even clouds of steam under the hood. This condition is critical because overheating causes the metal of the engine to expand, which can cause damage to important components such as the cylinder head or the cylinder head gasket. In the worst case, irreparable cracks can even appear in the engine block.
If you notice overheating, you should stop immediately and allow the engine to cool down. Do not try to open the hood immediately, as hot coolant can spray out. Have the cooling system checked professionally to determine the cause. Often the cause is a combination of increased pressure and other faults such as a defective water pump or a blocked radiator.
Rapid loss of coolant
If your vehicle Constantly new coolant If you need coolant without an obvious leak being visible, you should definitely take notice. In an overloaded cooling system, the coolant can be lost in various ways.
This is often done via the pressure relief valve of the expansion tank. This valve is intended to relieve the system if the pressure becomes too high and allows excess coolant to escape. However, small leaks that are difficult to detect, for example at the connections of the hoses or in the area of the radiator cap, can also be caused by the increased pressure.
These leaks are often difficult to locate, as the coolant evaporates as it escapes and leaves no visible traces.
How can you fix the problem?
If you notice that your cooling water is forming bubbles, smells unusually of exhaust fumes or is even bubbling out of the top of the expansion tank, this is a clear alarm signal. These symptoms indicate that too much pressure is building up in the cooling system - usually caused by combustion gases entering the cooling system from the combustion chamber. A defective cylinder head gasket is often the cause, and this can result in serious damage to your engine if it is not repaired in time.
In many cases, however, such a problem can be effectively solved with Steel Seal provided that the application is carried out correctly and the pressure in the cooling system is reduced in the meantime. Steel Seal is an inexpensive and simple alternative to mechanical repair that seals the leaking area of the cylinder-head gasket. But be careful: there are some important points you should bear in mind to achieve the best possible result.
The problem: pressure as a disruptive factor
The pressure in the cooling system poses a major challenge when using Steel Seal. Why? The excessive Compression pressure from the combustion chamber acts as a counter-pressure on the leak between the combustion chamber and the cooling water channel. As a result, Steel Seal cannot work optimally. The bonding process - i.e. the sealing of the damaged area - is hindered because Steel Seal cannot penetrate into the affected areas. It is therefore important to minimize this pressure or, ideally, to neutralize it completely.
The solution: Reduce the pressure during application
The good news is that there is a simple way to reduce the pressure during the application of Steel Seal: Leave the radiator cap or the cap of the expansion tank removed. This allows the built-up pressure to escape, making it easier for Steel Seal to reach the defective area of the cylinder-head gasket.
In practice, this measure is sufficient in two out of three cases to successfully rectify the problem. However, if bubbles are still visible in the coolant or the pressure is not reduced sufficiently, there is a supplementary method to maximize success:
- Identification of the affected cylinder: Determine which cylinder is generating the compression pressure that is escaping into the cooling system. You can find this out with a compression tester or by using the exclusion principle:
- Remove each spark plug (or in the case of diesel: the glow plug) in turn.
- Start the engine and observe in which cylinder the bubbles in the expansion tank subside. This will help you identify the leaking cylinder.
- Pressure relief on the affected cylinder: Remove the spark plug (or the glow plug) and, if possible, the injection line of the leaking cylinder. This will prevent fuel from entering the combustion chamber and eliminate the compression pressure.
- Application of Steel Seal: Start the engine with the remaining functioning cylinders. Steel Seal can now penetrate the affected area unhindered. If the engine with one cylinder less has difficulty getting up to operating temperature, you can accelerate slightly to increase the engine speed and support the process.
- After application: Reinstall the spark plug or glow plug and the injection line and check whether the problem has been solved.
What can you do preventively?
To prevent excessive pressure in the cooling system in the first place, you can take a few preventive measures:
- Regular maintenanceHave your vehicle's cooling system checked regularly. All hoses, seals and the radiator cap should be checked for proper function.
- Use high-quality coolant: Make sure you use the coolant recommended by the vehicle manufacturer. This not only offers the best performance, but also prevents deposits and corrosion.
- Fix leaks immediatelyEven small leaks in the cooling system should not be ignored. They not only lead to loss of coolant, but also allow air to penetrate.
Long waits can be expensive
Excessive pressure in the cooling system is not a problem you should take lightly. Even if the symptoms may seem harmless at first, they can quickly develop into serious damage. By knowing the causes and reacting immediately, you can avoid major repair costs and extend the life of your engine. If you notice any symptoms, check the system or have a specialist take a look.
Always remember: your vehicle often shows you early on when something is wrong. Listen to these signals - it will be worth it!
Further contributions:
Was verrät Dir der Öldeckel über deine Zylinderkopfdichtung?
The cylinder-head gasket is an important component of your engine. It ensures that the oil, coolant and combustion chamber are perfectly separated from each other.
Checking the cylinder head gasket - how it works
The cylinder-head gasket ensures that the oil, coolant and combustion gases remain safely separated from each other. As soon as it is damaged, serious problems can arise.
