Skip to main content

Why does the air in the cooling system cause the system to overheat?

 When a cooling system leak occurs, the pressure of the liquid reduces, and the boiling point of the coolant/antifreeze drops as well. Cooling systems are pressurised to raise the fluid's boiling point, with the pressure cap and overflow assisting in raising the temperature at which the coolant or antifreeze boils.

When a head gasket blows, air enters the cooling system, causing bubbling. At the same time, coolant/antifreeze leaks from the head gasket into the cylinder head. This implies that when the liquid seeps into the cylinders, the cooling system gradually fills with air, lowering the liquid pressure and causing the fluid to boil. Overheating can occur quickly with a head gasket leak, with white steam flowing from beneath the bonnet.

air conditioner car cooling system

If the pressure at which the coolant/antifreeze flows through the engine is impacted by a leak, the fluid will reach boiling point, causing the engine to overheat, whether it's due to a malfunctioning pressure cap or a fracture in the engine block.

If you check MOT history of your car, you will maybe surprised to see that your car failed on the emissions test and the overheating engine could well be at fault.

What is the temperature at which coolant/antifreeze boils?

The temperature at which coolant/antifreeze boils is determined by the product's quality as well as the pressure maintained within the cooling system. Coolant/Antifreeze has a boiling temperature of 129°C and a freezing value of -37°C at normal operating pressure.

However, if the cooling system's pressure is compromised by a leak or a damaged component, such as a blown head gasket, the coolant's boiling point will drop as the system's pressure declines. As a result, when your automobile develops a defect or leak, it might overheat, causing the coolant/antifreeze to boil in the system.

How does air enter the system, and what can I do about it?

As previously said, there are a variety of reasons why air can enter the cooling system, ranging from small to major technical faults. We've included some of the locations that are prone to failure and can allow air into the system:

1 – Head Gasket

When a head gasket fails, pressurised air from the cylinders enters the cooling system quickly, causing the reservoir to bubble and coolant/antifreeze to leak into the cylinder head. This can soon cause the engine to overheat, and you should pull over before it gets any worse.

Symptoms:

·       Overheating

·       Bubbles in the coolant/antifreeze reservoir

·       White smoke from the exhaust

·       Billowing steam from under the bonnet

The Fix:

One alternative is to book an expert mechanic to repair the leak. However, this may be costly, so if you want to save money, you can apply a leak repair fluid at home. These do create safe, long-lasting repairs if you properly follow the directions.

2 – Coolant System Pressure Cap

To keep the system at a consistent pressure while enabling coolant/antifreeze to flow to the expansion reservoir, cooling systems rely on a pressurised cap. If the cap fails or is changed with one that is incompatible with the system, air can enter the system and create issues.

Symptoms:

·       Bubbling in the coolant/antifreeze reservoir

·       Bubbles around the cap seal

·       Overheating

The Fix:

If the pressure cap develops a malfunction, it must be changed before the pressure shift causes damage to the radiator. Ensure that the cap is replaced with an OEM (original equipment manufacturer) or a manufacturer-recommended component.

3 – Air Pockets in the Radiator

As coolant/antifreeze passes through the engine, air pockets in the radiator can cause blockages. When not enough coolant/antifreeze is given to the system following a coolant/antifreeze flush, any leftover air is expelled.

Symptoms:

·       Bubbling in the reservoir.

·       Higher operating temperature, which could lead to overheating.

·       Potential radiator damage.

The Fix:

After flushing the radiator and cooling system, run the engine for 15 minutes with the pressure cap off after refilling the system. Before replacing the pressure cap, drain any air from the radiator and cooling system.

What Does Bubbling Coolant Mean in a Car?

To circulate coolant/antifreeze around an engine, car cooling systems use a sealed network of pipes. These hoses are connected in a sealed loop, allowing coolant/antifreeze to flow smoothly and continuously to components such as the head gasket, cylinder heads, and engine block, keeping the engine running at the proper temperature.

When air is let into this enclosed system, it can cause clogs and bubbling, which can cause the engine to overheat. There are various probable explanations for air pockets in the cooling system, which we'll go over in our guide to what coolant/antifreeze bubbles in the system imply.

An overheated engine can also lead to an MOT failure due to the emission test carried out by the examiner. It is suggested that you check MOT status of your car and book your car with your local mechanic to have this matter resolved beforehand.  An overheated engine will not only lead to a possible MOT failure but can also lead to total engine failure.

Why is the coolant in my car bubbling?

Most vehicles have pressurised cooling systems that rely on a leak-free closed circuit of hoses to circulate coolant/antifreeze around the engine. When air enters this enclosed system, air pockets can develop, causing clogs and bubbling, as well as overheating.

As soon as you detect your car overheating, search for car garages near me online and book your car in with a qualified mechanic to repair it. There might be a number of issues, or it could be something as simple as air in the coolant system, requiring a coolant service.

Bubbling shows that the cooling system's air pressure is rising, indicating that a pocket of air is blocking the flow of liquid. A blown head gasket, in which the air pressure inside the cylinder heads is transmitted to the cooling system, is one of the most typical reasons. This escaping air generates bubbling in the coolant/antifreeze reservoir, which is sometimes misinterpreted as boiling.

When you next book your car in for an interim or full service, it may be useful to search for car services in Reading and also book your car in for a coolant service at the same time.

There are a few additional reasons for air within the cooling system besides a blown head gasket, which we'll discuss later.

Comments

Popular posts from this blog

4 Signs Your Exhaust Pipe Is Weak or Broken

  In their regular operation, internal combustion engines emit what is known as exhaust. After combustion, exhaust gases leave the engine's cylinders and travel through the car's exhaust system before being expelled via the tailpipe. A network of metal pipes makes up the exhaust system, which moves exhaust fumes to the back or sides of the car so they may be safely let out. Even though it has a straightforward design, the exhaust system is crucial to engine performance. According to the online MOT history checker , the emissions test is frequently to blame for a MOT test failing. The typical signs of a damaged exhaust downpipe include an extremely loud or stinky exhaust, issues with the engine's performance, and a dangling or dragging exhaust pipe. Any difficulties with the system or its pipes could make the car difficult to drive. The driver can be made aware of a potential problem by a few indications that are typically produced by a defective or malfunctioning exhaus

Can you fail MOT for no washer fluid?

  Notwithstanding being a straightforward check, such countless individuals bomb a MOT test for having no washer liquid. You ought to routinely check your screenwash level whether or not your MOT test is expected as, particularly in helpless driving conditions, your windscreen can before long become covered and confine your perspective out and about Look for a  garage in Reading  and as per the manufacture’s recommendations, book your car in with a mechanic to have the cabin filter replaced. Can you fail MOT for low petrol? Yes a MOT tester can reject to do MOT test of your car because mechanic need petrol for the MOT test checking exhaust and for running the engine. Should I warm car up before MOT? Heating up the motor before a MOT is one method for forestalling unnecessary degrees of smoke being delivered during testing. The actual fumes will be checked for commotion, and to guarantee any impetuses which were fitted when the vehicle was produced are still set up. Car Ser

What does a full service on a vehicle include?

  Checks during a car service can include the engine oil, oil filter, lights, tyres, bodywork, exhausts, brakes, steering, fluid and coolant levels, suspension and 12V battery How long does a full service last? A full car service is a complete check of the whole car, which should be carried out annually or every 12,000 miles. This service can take around 3 hours to complete Are spark plugs changed in a full car service? A full service usually includes everything apart for any parts specified as requiring replacement in your vehicles servicing schedule, such as fuel filters, spark plugs etc. How far back can you check MOT history ? Records are held for up to 10 years, so you will be able to check a detailed history of the vehicle, including: Its MOT passes and failures. Which parts of the vehicle failed the respective test? How long does MOT status take to update? It can once in a while require as long as 5 days for the MOT expiry date to be refreshed after you present yo