Radiator Cap Functions and Malfunction Symptoms

Although the name suggests that the radiator cap is just a normal cap holding the coolant inside the radiator, that’s only half of its function. The radiator cap is actually a two-way valve, holding the coolant inside, like we said, but also maintaining system pressure.

How does a radiator cap work? 
When you heat a liquid to a certain point, it starts to boil and eventually vaporize, changing its properties by going from a liquid to gas. In normal conditions, water boils at 212 degrees Fahrenheit, but by pressurizing it we can raise its boiling point substantially. Cooks do this all the time. They use a pressure cooker to cook food faster thanks to the hotter water inside. This is the same concept with the radiator cap and the radiator.

The pressure inside the radiator is kept at 16 pounds per square inch (in most cases), and it’s all regulated by the radiator cap. It’s a very delicate system. If the pressure isn’t maintained, the coolant can boil and evaporate, putting the engine at risk of overheating. On the other hand, if the pressure builds up too much you better hope that a hose lets go before the radiator ruptures. If that happens, you’ll be looking at a brand new radiator, and those aren’t cheap.

Radiator cap malfunction symptoms
As such, detecting a bad radiator cap early can be extremely good on your wallet and watch. A skilled mechanic can check whether your radiator cap is fit for the job in less than five minutes, but if you want to do it yourself or simply want to learn about inspections and the symptoms of radiator cap, continue reading this article.

The first symptom is coolant leak, whether it be from the radiator or the cap itself. A punctured radiator can be the result of a bad cap. The cap doesn’t just let go suddenly. In most cases, there are some tell-tale signs, the first one being coolant escaping from your cap.

Another obvious symptom is engine begin to overheating. If the coolant has escaped or isn’t allowed to move freely, you might notice your engine temps rapidly rising. If that’s the case, you want to immediately stop or you risk overheating the engine, which is never a good thing.
Read also: Symptoms of a bad idle control valve

Radiator cap inspections
Check the leaking in cap area

If you notice liquid around the edges of the cap, investigate further. With a bad cap, you can even hear antifreeze bubbling away sometimes. But be careful. Do not open the cap until the car and the coolant have a chance to cool off. Opening the cap when the car is hot can seriously scar you if the hot coolant sprays all over you (and it usually erupts like a geyser).

Check the plunger condition

The spring-loaded plunger in the cap can get jammed, trapping the coolant in a certain place, restricting access from the cooling system to the overflow reservoir. A quick visual inspection of the overflow reservoir will show if that’s the case

Test the radiator cap using pressure gauge

The cap can also be tested with a pressure gauge. If the pressure drops when testing it, try to clean the cap and test it again. If it gives the same results again, it needs to be replaced. Replacement caps are easy to come by. They’re very cheap and all you really have to do is buy one with the exact same pressure rating. Again, make sure that the car has cooled down before replacing the radiator cap if you want to avoid burns.

5 Symptoms of a Clogged Radiator

As the engine runs, it produces heat. The purpose of the radiator is to cool the engine and prevent it from overheating. You use coolant to push this heat into the radiator which is where it actually cools down. Once that happens, the coolant is sent back into the engine and the process starts over again.

Symptoms of a Clogged Radiator
The cooling system depends on the radiator above all other components. If the radiator does not work well, then there will be no cooling taking place inside the engine. That is why if you have any reason to believe the radiator may be clogged, pay attention to see if you notice one of these symptoms happening that are listed below. If you do, then it is likely a clogged radiator that you have.

1) Overheated Engine

Since a functional radiator prevents the engine from overheating, you will know something is wrong with the radiator if the engine starts overheating. Monitor the temperature gauge and see how often it stays on the hot side. If you see the gauge pointing toward the hot side, even when the air conditioner is turned on, then you may have a clogged radiator. The vehicle will also consume more coolant too. The reason that a radiator gets clogged in the first place is from corrosion, internal deposit buildup, and debris which tends to happen over time. With the radiator being clogged like this, very little coolant is able to make it into the radiator.

2) Hotter Temperature Inside

Sometimes it may be harder to heat up your car if the radiator’s heater core has debris clogging it too. With the heater core clogged, coolant in the engine cannot get into the core in order to bring heat inside the car.

3) Leaky Coolant

The housing or cooling fins may have corrosion forming on them when radiators are clogged. Once this happens, you will be able to see the coolant leaking very easily. If you don’t fix the leak as soon as possible, the radiator may get damaged beyond repair.

4) Damage to the Water Pump

You will have a faulty water pump if parts of the coolant system and the radiator become clogged. If a water pump cannot function properly, then the coolant will not be able to circulate properly either. This could cause coolant leaks which will eventually result in damage to the engine.

5) Damage to the Cylinder Head Gasket

If you have a radiator that’s clogged, coolant won’t be able to circulate. Therefore, the engine will overheat and the head gasket in the engine will stop working. As a result, coolant will get into the oil compartment of the engine and create all kinds of problems and damage that are irreversible.

Conclusion

To figure out if you have a clogged radiator, try using something called an infrared thermometer. Either that or conduct a radiator efficiency exam by measuring the coolant temperatures going in and coming out.

Sometimes you can simply clean a clogged radiator to fix the problem while other times the radiator will need to be replaced if the problem has been left for too long.

How Often Does My Car Need a Radiator Flush?

A radiator is part of the internal combustion cooling system in a vehicle. It is a form of heat exchanger, designed to transfer heat from the heated coolant mixture as it flows through the vehicle.

Radiators operate by pushing hot water from the engine block through tubes and fans that allow the heat from the water coolant to dispel. Once the liquid is cooled down, it is returned to the engine block to absorb more heat.

The radiator is usually mounted in front of a vehicle, behind the grill, to take advantage of the air that flows as the vehicle is being driven. Those with a fan normally have either an electric fan; that is usually mounted on the radiator, or a mechanical fan that is mounted on the engine.

Cars that have an automatic transmission, however, have a cooler included in the radiator for hot transmission oil.

What is a radiator flush?

A radiator flush is done to prevent a vehicle from overheating and help maintain an efficient radiator system. This procedure is done by draining the original coolant from the radiator and replacing it with a new coolant or antifreeze mixed with water. The mixture or solution is then left to circulate through the vehicles’ cooling system so that it can dissolve and remove any solid build up inside the radiator channel. When circulation is complete, the coolant or antifreeze mixture is then drained and replaced with the standard mix of coolant and water.

How often is a radiator flush needed?

There is no set rule for how often a vehicle needs a radiator flush. Car manufacturers recommend that it be done at least every other year or every 40,000 to 60,000 miles.

Occasionally flushing the radiator before that period is not a problem as it helps to clean and prevent build up of dirt and sediment. Fresh antifreeze also contributes to protecting a vehicle from extreme cold or hot temperatures.

A certified mobile mechanic from AutoFactorNG can come to your home or office to flush your coolant or inspect why your car is overheating.