Car coolant reservoir contains the hoses, pipes, and pumps for fluid movement in the engine compartment. The liquid flows between the engine parts through the enclosed system and maintains the internal temperature.
Why is My Coolant Reservoir Boiling and Overflowing? Car Coolant reservoir boiling and overflowing is due to leakage in the hose system, damaged pressure caps, blown-out head gaskets, and improper flushing of radiators. The issue also comes due to a clogged radiator, water pump failure, a bad thermostat, and faulty temperature sensors. In addition, the low coolant level and bad cooling fan cause the boiling of antifreeze.
The overflowing of the coolant system is common in cars with turbocharged engines. These are high-efficiency engines that overheat in the summer season. Moreover, driving at high speed with a turbocharged engine cause overflowing problem.
Leakage of hose systems
The hoses are the sealed network of pipes through which coolant moves in the engine to regulate the temperature.
The cracks or leakage in these pipes cause the air to enter the system. The temperature of the coolant also falls due to cracks in the hoses.
The pockets of air form in the hoses, and it blocks the movement of the fluid, which ultimately causes overheating.
The hoses cannot maintain the temperature and cause boiling or bubbling formation. As a result, the hoses are more susceptible to wear out, and cracks are formed in them with time.
In addition, the corrosion on their surface also causes damage and forms holes in these pipes. Finally, these parts rub continuously with the components of the engine compartment, which can cause abrasion.
The contamination is the primary reason for the cracking of these hoses. The oil and grease come in contact with them and make them bad.
You can check their leakage by seeing the colored stains on the sides of the radiator. However, it is also better to check the source of the oil leakage and fix it.
Moreover, avoid using clamps to fix the damaged hoses because inaccurate fixing cause leakage of antifreeze.
Damaged pressure cap
The pressure caps are present on the radiators to maintain the internal temperature while regulating the pressure.
These caps are located on the top side of the reservoir cap, so coolant or water cannot come outside in the form of steam.
You need to check the position of these caps. Sometimes they do not remain in their place and disturb the pressure inside the hoses.
In addition, the caps also get damaged due to overheating issues in the engine compartment. The displacement from their correct position occurs due to compression.
Internal pressure fluctuations of the coolant reservoir cause their displacement from their original location.
It is better to change it every 3 to 5 years to maintain the correct temperature and pressure of the antifreeze.
Ensure the cap size before replacing them because inaccurate size also causes air entry and pressure changes.
Improper flushing of coolant
The air formation in the radiator reservoir causes overflowing and boiling problems. The flushing of the reservoir with the addition of more coolant removes the air bubbles and air pockets.
The flushing process is not difficult, but it is quite challenging. Therefore, you need special care and proper handling while doing this.
An adequate amount of coolant is necessary for the flushing procedure. You cannot remove the air completely if you do not add enough fluid.
The air pockets remain in the radiator and disturb the temperature and pressure from the normal points.
You can fix it by calling the mechanics because you are not an expert like them. Moreover, pour a sufficient amount of antifreeze to remove air bubbles completely.
Failure of the water pump
The water pump is the coolant pump that regulates the movement of the antifreeze after getting power from the engine.
This pump maintains the engine’s temperature at the optimum level. The water pump failure in cars causes steam and overheating in the hood.
The failure occurs due to improper lubrication of this part. In addition, it can also wear out when you drive your vehicle more.
The electric motor is more susceptible to wear out with time. The use of low-quality and contaminated coolant in the reservoir also causes damage.
You can fix it by checking the alignment of the belt and slightly loose them if they are too tight. Remove the corrosion from their sides due to low-quality ad contaminated fluid.
The thermostat is the valve-like material present in the engine compartment and separates the radiator fluid from the engine parts.
The fluid reaches the engine component when the temperature fluctuates from normal conditions.
This thermostat maintains the engine parts’ temperature while maintaining the coolant’s flow.
These valves do not open and close at the correct time, which can cause overflowing of the coolant in the car, and you can feel the overheating issue.
The debris in the valves also causes these valves to get stuck in the open position, which is problematic.
The damaged or broken return springs also affect the functioning of the thermostat.
You can fix it by removing the old fluids from the reservoirs because they can contain dust and cause contamination.
Checking its return springs and replacing the broken ones is also better.
The clogged radiator cause problem with the accurate flow of the coolant reservoir through the hoses and pipes. The fluid cannot reach the engine compartment for maintenance of temperature.
The most common reason for clogging is the accumulation of rust. In addition, you can also face the problem due to the presence of dust and debris.
Driving the car on dusty roads causes this problem. You can fix the issue by draining the fluid from the radiator and engine blocks.
Try the flush method to remove the reservoirs’ dust, debris, and corrosion.
Low coolant levels
The bubbling formation of the coolant and boiling indicate the high temperature of the antifreeze that can occur due to its low levels.
The levels become low due to leakage from the hoses. The fluid levels become low when water is evaporated from them in the form of steam.
It is better to check the levels when you feel the sweet smell from the engine. In addition, more fuel consumption also indicates their low concentrations.
It is essential to check the reservoirs and add the pour new coolant when their levels are low. You can also see the warning signs on the screen of your car.
Faulty temperature sensors
The coolant temperature sensors are present to measure the temperature of the antifreeze solution. The temperature measurement gives the estimate of heat production from the engines.
The sensors stop working when there is a problem in the computerized system of the car.
The fluid starts to boil and overflow when the temperature does not show the correct reading. This is because it cannot flow in the engine blocks because of the wrong reading of these sensors.
The faulty coolant temperature sensors also cause the overheating of the engine. You can fix it by attaching the scanner tools to the onboard system of your vehicle.
The scanner tools give the faulty codes, and you can resolve the problem easily.
Cooling fan problems
The primary function of the cooling or the radiator fan is to maintain the temperature of the moving fluid. However, the bad cooling fans cannot keep the radiator cool which can cause overheating in the reservoir.
The failure comes due to the accumulation of rust in its parts. Moreover, faulty wirings and loose connections affect their working.
The fans cannot spin due to broken wires and a blown-out fuse. Check the functioning of the radiator fan when your engine shuts down during driving because of overheating.
Replace the broken fuse and check the electrical wiring.
Blown out head gaskets
The head gaskets in the cars act as a barrier between the cylinders and the engine blocks.
These provide the seals to the engine blocks to maintain air pressure in the combustion chamber.
The head gaskets blow out when they become old. Moreover, the damage occurs due to corrosion, grease exposure, and engine oil.
The blown-out head gaskets cause the entry of compressed air from the cylinders into the cooling system.
The presence of air causes overheating in the reservoir, overflowing, and can damage the engine. However, you can fix the issue by cleaning the gaskets correctly.
Remove the dust, debris, and oil residues from their surface. Then, use the correct size of head gaskets to seal the cylinders for their proper attachment.