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How to Clean a Radiator With Baking Soda (Step-by-Step)

A car radiator is a crucial component of a vehicle's cooling system. It helps to keep the engine from overheating by dissipating heat through the use of coolant and a network of fins.


However, over time, a radiator can become clogged with rust, debris, and other contaminants, which can decrease its efficiency and lead to costly repairs.


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 the common questions about using baking soda to clean a cars cooling system.


Table of Contents:


baking soda in a glass jar with a pink background

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.


car radiator

Signs of a Clogged Radiator

Below are some of the common signs of a clogged radiator which may need to be flushed.


  • 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.

  • 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.

  • 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.

  • 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.

  • 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.


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.


How to Flush a Radiator With Baking Soda

Flushing a radiator with baking soda is a simple and effective way to remove debris and buildup that can clog the radiator and decrease its efficiency. Below is a step-by-step guide on how to flush a car radiator with baking soda.


  1. 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.

  2. Prepare the equipment and materials: Gather all necessary equipment and materials, including rubber gloves, eye goggles, baking soda, water, a bucket, and a funnel.

  3. 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.

  4. 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.

  5. Open the radiator cap: Carefully remove the radiator cap to allow access to the coolant and allow for easier coolant drainage.

  6. 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.

  7. Add the baking soda solution: Using a funnel, add the baking soda solution to the radiator.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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 put vinegar and baking soda in a radiator together, baking soda can be used before or after flushing a radiator with vinegar.


When baking 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 basic solution), a chemical reaction occurs that produces carbon dioxide gas, water, and a salt called sodium acetate.


This reaction is known as an acid-base reaction, and it creates a fizzing and bubbling effect.


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