We believe that you already know how vital a radiator and coolant are for your vehicle’s engine and cooling systems. Well, in simple words, the radiator cools down the flowing coolant and ensures that the engine receives nothing but cooled-down antifreeze.
But did you know that the radiator cap plays a significant role too? Well, it does! And it is not just only about properly sealing the radiator, which we learned the hard way.
We drove around in a car that had a bad radiator cap. And during that period, we probably faced all of the bad radiator cap symptoms. So, if you were looking for a source that describes them all, you just found the right one!
Signs of a Faulty Radiator Cap
As we mentioned, we drove around a car with a faulty radiator cap for almost a month. And these are all of the issues that we have faced during that period:
This issue is one of the most common signs of a faulty radiator cap. As the cap seals the radiator and creates the right amount of pressure to make the coolant flow in the right direction, the antifreeze will find a way out when it is faulty. And all of those leaked coolants will come out through the front of the vehicle.
As the system is losing antifreeze, your vehicle will be forced to run on a low level of coolant. That means the engine will not remain at the optimal temperature. You will notice the check engine indicator glowing up on the dashboard. Also, the coolant temperature dial or gauge will freak you out too.
Even if there is not that much coolant lost and the system has a good amount inside the reservoir, the engine can still overheat. Do you know why? Well, the cap maintains the correct pressure inside the radiator. And that pressure ensures that the antifreeze is flowing at the right speed through the pipes and radiator.
When the coolant flow is not optimal, the engine does not get adequately cooled. And that would overheat the engine and its parts, which will make the dashboard indicator
White Streaks on Radiator
So, after noticing all the indicators on the dashboard going crazy, we decided to pop the hood up. And that is when we noticed what the exterior condition of the radiator was. The leaks that dried on top of the radiator left a white residue on the surface. Also, there was a good amount of it on the cap region.
You might know by now that the coolant makes a full circle from the reservoir. And when the coolant that is leaving the container is not coming back to the same place, the level will drop significantly. We noticed that we lost almost 80 percent of the total coolant inside the reservoir in just a month.
We even noticed the hose collapsing while the radiator cap was faulty. And no, this is not something that was applicable for us only. After talking to a mechanic, we found out that lack of pressure makes the hoses collapse. So, when you notice such a thing after popping open the hood, it is probably the radiator cap.
Radiator Hose Burst
When the radiator cap is loose, the air pressure inside the cooling system and its parts can increase suddenly. And that increase in air pressure will make the hose expand abnormally. Sometimes, the pressure will not be enough to rip the hose in half, but it will make the hose obtain a weird shape or deform.
Furthermore, there might be a less severe burst or crack on the hose due to the high pressure. That will make two leaking points, which will make the reservoir run out of coolant exceptionally fast. You will notice a puddle of the coolant at the place where you parked the car for a while after this happens.
Air Inside the Cooling Components
When the radiator cap is loose, the seal will not be proper. And that would make the air get inside the core components. These air pockets can get inside the heater core, which can make the engine overheat. Furthermore, the air pockets can cause the leak to be severe if the hoses have a crack or are burst.
What Should You Do When the Cap Is Faulty?
First, you need to make sure whether the issues that you are facing are for the cap or not. A simple inspection goes a long way. Check the lid and if there are any residues present on the surface or not.
Then, opt for a pressure test on the radiator. If the pressure is not optimal, get the cap replaced. That should solve all of the issues that you are facing at the moment.
As you can see, the bad radiator cap symptoms range from mild to extremely severe. So, whenever you notice any of the signs that we have mentioned above, you should check the cap and the other parts of the cooling system as soon as possible.