How to Clean the Radiator Inexpensively

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Tip on how to clean better a vehicle's radiator. Better than the conventional way.

Many car problems can be avoided with good maintenance practices. One of those maintenance routines is cleaning the radiator. Cleaning the radiator makes the cooling system much more efficient and the engine is kept cool. A cool engine makes the car run at its peak performance.

The usual way of cleaning a car's radiator is to drain the radiator by removing the plug underneath it. But this is not thoroughly effective in removing the muddy sludge that accummulate inside the radiator through time. Chances are, the coolant or water circulating in the engine is still not free of dirt that may again build up and possibly clog the cooling system.

A much more effective way of flushing out dirt and cleaning the radiator thoroughly is  by performing the following technique. This will require simple materials and skill to perform.

What You Will Need

  • an improvised extension tube
  • a garden hose
  • source of water
  • screwdriver
  • masking tape
  • coolant collector


It will be best to perform this procedure in the morning when the engine is cool. If the vehicle has been in use, let it cool down before doing the following steps.

1. Unscrew and remove the radiator cap. Drain the coolant from the radiator. Make sure that you have a coolant collector to prevent it from contaminating the drainage system. Coolants contain glycol, a toxic material. If water is used as coolant, then there will be no need to drain it.

2. Remove the clamp that fixes the hose that serves as a channel to recirculate water from the engine back to the radiator. You will need a screwdriver to remove it.

3. Connect the improvised extension tube to the hose that drains water from the engine. An extension tube can be made out of any material around the house that will serve the purpose. The author used a potato chip container. A masking tape was wrapped around the other end after cutting out a hole in the cap that fits well with the outlet tube. The bottom end of the tube was also removed. The tube should be oriented towards the front of the radiator to flush out water coming from the engine.

4. Connect a garden hose to a nearby faucet that will serve as source of water. Place the other end of the garden hose into the radiator opening on top of the radiator. 

The set-up should look like this.

improvised radiator flushing system

4. Cover the upper inlet of the radiator with a masking tape to prevent the coolant or water from spilling into the engine as dirty water is flushed out.

5. Switch the engine on and supply the radiator with water from the garden hose. As the water is flushed from the engine through the extension tube, a fresh supply of water from the faucet or other clean water source replaces lost water.

The drained water will at first look muddy and brownish. Continue idling the engine until the water coming out of the radiator becomes clear. Let the engine run for about 3 to 5 minutes. Make sure that the water supply compensates for the lost water from the engine.

Once the water is clear, switch off the engine. Remove the improvised extension tube and replace the outlet hose back to the radiator's inlet for circulating water. Clamp this firmly to prevent any leak. Fill the radiator with coolant or water and screw back the radiator's cap.

You should be able to experience better car performance after applying this simple procedure to flush out sludge or dirt from the radiator.


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