Coolant smell from vents is often a problem many drivers will face, especially after winter is over. What is the cause of this strange odor?
How to completely remove it? Let’s dig in to discover more useful information.
What Are Common Causes Of Coolant Smell From Vents?
Common causes of coolant smell from vents are coolant leaks from the reservoir, valve and heater core radiator and head gasket.
Besides, loose connectors also trigger coolant leaks, leading to a sweet smell from the car vents.
Coolant Leaks
The most common cause of the car smells like antifreeze when AC is on is the coolant leaking. You can observe and spot a few obvious signs.
The most noticeable one is a puddle of coolant underneath the car compartment.
It shows that your car’s coolant has leaked from a pipe or another deep inside, dripping into a puddle underneath the vehicle.
A cracked, punctured pipe or a torn radiator in the vehicle can lead to this fluid leak.
In addition, the leak is also triggered by a leaking radiator cap, damaged cylinders, damaged pump, and faulty auxiliary engine coolant.
If you don’t see any coolant dripping out, it may have leaked into other internal components due to a puncture. The most likely explanation is that the coolant in your radiator dries out too quickly.
Cracked Coolant Reservoir
The antifreeze smell in vents also originates from cracked coolant reservoirs. This reservoir stores an adequate coolant amount to keep the engine running efficiently.
If it leaks, the coolant level will drop and cause the engine to overheat, followed by serious damage.
Some leaky coolants don’t have any smell, so sometimes you’ll find that the coolant dries out too quickly but doesn’t detect anything out of the ordinary.
The only way to check whether the reservoir is cracked is to look under the hood and inside the reservoir to check. If you can’t find the cause, you need to ask the mechanic for an inspection.
Valve & Heater Core Leaks
Heater core, valves, and cooling system work together to distribute coolant to the components of your car.
If the heater core or valve leaks, you will detect the antifreeze smell coming from vents when turning on the air conditioner.
You can detect a valve leak when you see coolant dripping or spreading to neighboring parts in the hood compartment of the car.
It can also be spotted by leaving traces of leaks at the location where you park your vehicle.
You can easily notice the heater core leak through the fog on the windshield because a lot of steam will escape when it leaks.
Although it is relatively easy to spot, there could be more leaked spots than you think.
If the coolant drains quickly after you’ve repaired a previous leak, there may still be another leak inside that you haven’t discovered yet.
Untightened Connectors
Normally, connectors connect valves with other parts of the cooling system and others of the vehicle.
Driving for a long time on rough roads makes these valves loosen, entailing a leak of coolant fluid and an antifreeze smell in car vents.
You should see this liquid dripping from the valve and connector mounting locations. The more the coolant drips, the looser the connection is. So you can easily solve it by tightening these connectors.
Radiator & Head Gasket Leaks
When you spot an antifreeze smell coming through vents and see blue or white smoke rising from your car’s exhaust, then the head gasket leaks due to rust or cracking.
You will also find that the engine is hotter than usual, and a broken head gasket can cause the coolant to blow out of the reservoir.
The smell of antifreeze coming through vents changes depending on the season. In the spring, you will know this smell is stronger because you do not use the air conditioner much in winter.
Also, if you’ve checked and determined the smell isn’t caused by the coolant leak, it could be due to mold and dirt build-up in the vents or the filter.
A leak in the radiator is also the culprit behind this coolant smell. The most obvious sign is that the coolant is bubbling in the reservoir when you open the hood.
The radiator may have been severely damaged, and you probably need to take your vehicle to a repair shop to replace it.
How To Fix If Your Vents Have Coolant Smell?
Check AC’s Parts & Replace
If you check and find parts such as the coolant reservoir, valve, heater core, radiator, or head gasket leaking, you should repair it immediately.
Usually, the easiest problem to solve is loose connectors since you can screw them tight without spending any money.
Most of the remaining parts, once rusted or damaged, need to be replaced. To make sure, you should go to genuine car dealers for repair and replacement if necessary.
Replacing or repairing a leaky core heater is the most expensive, around $250-$900, as it’s a pretty important part and requires meticulous repair.
Replace The Coolant
Replacing the coolant or radiator fluid is also an idea to try because many coolants have a rather sweet smell. You can go to auto parts stores to find out which coolant is odorless or has a slight odor.
Coolant replacement can be easily done at home. You can refer to your vehicle’s owner’s manual and follow the steps.
Should you not confident, you can go to car repair shops and ask them to help you.
FAQs
What Are Common Signs Of Coolant Leak?
The most obvious sign of a coolant leak is a rapid antifreeze drop or the engine heating up too quickly after refilling.
You will probably receive an overheated engine warning via a thermometer-like warning light on the dashboard.
Also, if you notice a strange smell coming out of your car vents, the antifreeze may have leaked somewhere. You can check by looking around and under the car to see any liquid deposits.
Normally, coolant liquid will have prominent colors such as blue, red, orange, and pink. It will also likely become discolored due to rusted radiators.
How To Find The Source Of The Possible Coolant Leak?
Whenever you notice a strange smell that is stronger inside the car than outside, the leak could be coming from internal engine components.
You can also check to see whether the coolant is leaking under the car by parking it somewhere for about 30 minutes.
In addition, you can inspect by yourself to confirm that the components inside the hood don’t have any problems. Check if the reservoir, valve, radiator, etc., are cracked or torn.
Do You Need To Replace Your Coolant Periodically?
Yes. It is extremely important because the coolant will lose its ability to resist corrosion after a long time of use.
It will be best to replace the coolant periodically to avoid causing the radiator or the pipes to corrode.
Changing the coolant will help reduce flow blockage and allow the driver to detect if the coolant is leaking. You should replace it about every 5 years and use the right coolant for your car.
Suppose don’t remember how long it’s been since the coolant has been changed; drain it and observe its color. When you see lumps and it’s brown, it’s time to replace your car antifreeze.
Conclusion
The main cause of the coolant smell from vents is coolant leakage due to cracks or damage from various components such as valves, reservoir, heater core, radiator, or head gasket.
You can handle it by changing the coolant periodically and taking your car to the mechanic to fix it if there are any problems.