How to Clean a Radiator With Baking Soda (Step-by-Step)
Updated: Feb 1
✔ This article has been fact checked.
A radiator is a crucial component of a vehicle's cooling system. It prevents the engine from overheating by dissipating heat through the use of coolant and a network of fins.
Over time, a radiator can become clogged with rust, debris, and other contaminants, which can decrease its efficiency and lead to costly repairs. You can clean and flush a radiator using baking soda.
In this article, we will provide a step-by-step guide on how to clean and flush a radiator with baking soda. We'll also answer some common questions about this method of flushing a cooling system.
Table of Contents:

What Does a Car Radiator Do?
A car radiator's main function is to dissipate heat from the engine and prevent it from overheating. The radiator is located in the front of the vehicle and is connected to the engine via hoses.
As the engine runs, it generates heat, which is absorbed by the coolant running through the engine.
The coolant then flows through the radiator, where it is cooled by passing through a network of fins. This process helps to keep the engine running at the correct temperature.

Signs of a Clogged Radiator
Below are some of the common signs of a clogged radiator which may need to be flushed.
It's important to note that these signs can also be caused by other issues, such as a malfunctioning thermostat or water pump, so it's always best to consult a professional mechanic for proper diagnosis and repair.
1. Overheating
A clogged radiator will not be able to dissipate heat as effectively, which can lead to the engine running at higher than normal temperatures.
This can be indicated by a temperature gauge that reads higher than usual or by a coolant temperature warning light on the dashboard. In severe cases, the engine may even shut off to protect itself from overheating.

2. Low or High Coolant Pressure
A clogged radiator can also cause low or high coolant pressure, which can lead to leaks and further damage to the engine.
The coolant pressure is what helps to circulate the coolant throughout the engine and the radiator, and if the pressure is low, it can lead to the coolant not flowing properly.
This can be indicated by a low coolant light on the dashboard or by visible coolant leaks.
3. Steam Coming From the Engine Bay
Steam coming from the engine bay is a clear indication that the radiator is not able to dissipate heat effectively. This can be caused by a clogged radiator, which can lead to the coolant overheating and turning into steam.

4. Rust or Debris in the Coolant
If rust or debris can be seen in the coolant, it is a sign that the radiator is clogged and needs to be cleaned.
The rust and debris can come from a variety of sources, such as corrosion or rust in the radiator or hoses, or from debris that has entered the cooling system.

5. Unusual Smells or Noises
If any unusual smells or noises are coming from the engine, it could be a sign that the radiator is clogged. The smells can come from overheating coolant, which can produce a sweet or burning smell, or from rust and debris in the coolant.
The noises can come from the coolant not flowing properly, which can cause knocking or ticking sounds.
How to Flush a Radiator With Baking Soda
Flushing a radiator with sodium bicarbonate is a simple and effective way to remove debris and buildup that can clog the radiator and decrease its efficiency. Below are step-by-step instructions on how to flush a car radiator using baking soda.
Allow the car to cool down: Before starting the flushing process, it is important to allow the car to cool down completely. The radiator and engine can become extremely hot, and attempting to flush the radiator while it is still hot can cause burns or other injuries.
Prepare the equipment and materials: Gather all necessary equipment and materials, including rubber gloves, eye goggles, baking soda, water, a bucket, and a funnel.
Find out how much coolant your vehicle takes: Different vehicles have different coolant capacities, so it is important to know how much coolant your vehicle takes before flushing the radiator. Check the owner's manual or consult a professional mechanic for this information.
Mix the baking soda solution: In a bucket, mix 5 teaspoons of baking soda with every 1 litre of water. Stir the mixture until the baking soda is fully dissolved.
Open the radiator cap: Carefully remove the radiator cap to allow access to the coolant and allow for easier coolant drainage.
Drain the old coolant: Locate the drain valve on the bottom of the radiator and open it to allow the old coolant to drain out. Be sure to catch the old coolant in a bucket or container for proper disposal. Once the coolant is fully drained, close the drain valve.
Add the baking soda solution: Using a funnel, add the baking soda solution to the radiator.
Allow the solution to sit: Allow the baking soda solution to sit in the radiator for 5-10 minutes to allow it to break down any debris or buildup.
Start the engine: Start the engine and let it run for 10-15 minutes to allow the baking soda solution to circulate throughout the cooling system.
Drain the baking soda solution: Drain the baking soda solution from the radiator using the drain valve on the bottom of the radiator. Be sure to catch the solution in a bucket or container for proper disposal.
Flush the cooling system with distilled water: Flush the radiator with distilled water to remove any remaining baking soda solution and debris. Repeat this process until the water runs clear.
Add regular coolant back into the vehicle's cooling system: Once the radiator is clean and the water runs clear, add the recommended amount of regular coolant back into the cooling system.
Close the radiator cap and test drive the vehicle: Replace the radiator cap and take the vehicle for a test drive to ensure that the cooling system is working properly.
Check the coolant level and top up as needed: After the test drive, check the coolant level and top up as needed.
It's important to note that this process should be done with caution and proper safety precautions, such as wearing rubber gloves and eye goggles. Also, it's always best to consult a professional mechanic for proper diagnosis and repair if unsure about the process.
Can You Put Vinegar and Baking Soda in a Radiator?
While it is not recommended to combine vinegar and baking soda in a radiator together, baking soda can be used before or after flushing a radiator with vinegar.
When bicarbonate soda is added to vinegar, a chemical reaction occurs that produces carbon dioxide gas and a liquid solution consisting mostly of water and a salt called sodium acetate.
However, it is important to note that this solution should not be added to a radiator as it can damage the metal and cause leaks.

What Happens When Vinegar Hits Baking Soda?
When vinegar (an acidic solution) is added to baking soda (a base solution), a chemical reaction occurs that produces the following.
carbon dioxide gas
water
a salt called sodium acetate
This reaction is known as an acid-base reaction, and it creates a fizzing and bubbling effect.
It is best to use vinegar and baking soda separately when flushing the cooling system to avoid any issues.
Is Baking Soda and Bicarbonate of Soda the Same?
They are the same thing. There are various names of baking soda, sodium bicarbonate is the chemical name and bicarbonate of soda is another name, they can all be used interchangeably.

Is Flushing Radiator With Baking Soda Safe?
Flushing a radiator with baking soda is generally safe, as long as the proper precautions are taken. It is important to wear protective gear, such as rubber gloves and eye goggles, and to follow the proper steps for flushing a radiator.
However, it is important to note that baking soda can cause damage to the metal and cooling system if left in the radiator for too long, so it is important to follow the recommended time frame for allowing the solution to sit in the radiator.
Can I Flush the Car Radiator Myself?
Yes, it is possible to flush a car radiator yourself, as long as you have the proper equipment and knowledge. However, if you are unsure about the process or if your vehicle has any unique features, it is best to consult a professional mechanic.

Conclusion
A clogged radiator can lead to decreased efficiency and costly repairs. One effective way to clean a radiator is by using baking soda.
Flushing a radiator with baking soda involves mixing it with water, adding the solution to the cooling system, running the engine, and draining the cooling system before flushing it again with distilled water.
It is important to follow the proper steps and use protective gear when flushing a radiator, and to seek professional help if unsure. Baking soda is a safe and effective way to clean a radiator and improve its efficiency.
Sources
Jeffery Ekweghi. https://autovfix.com/how-to-flush-radiator-with-vinegar-baking-soda/
Steve Maxwell. "How to Flush a Car Radiator". https://www.familyhandyman.com/project/flush-a-car-radiator/
Luka Kusic. "How To Flush Your Radiator With Vinegar Or Baking Soda (Is It Safe?)". https://vehiclefreak.com/how-to-flush-your-radiator-with-vinegar-or-baking-soda-is-it-safe/