How to clean a turbo diesel intercooler

Is your car underperforming?

An intercooler often accompanies turbocharged diesel engines to help remove the heat produced by air compression. If your intercooler fails, you might notice abnormal behaviour, including a lack of power and engine overheating.

So, how do you prevent the failure of your intercooler? Natrad has compiled a detailed guide on spotting symptoms and looking after your intercooler to avoid costly repairs.

A nationwide warranty covers Natrad intercoolers for your peace of mind. If you need a replacement intercooler, contact your nearest store today.


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How to clean a turbo diesel intercooler

turbo diesel intercooler

Sometimes, all your intercooler needs is a good cleanout. Your heat exchanger works like a radiator but can sometimes become clogged or blocked. Depending on the type of intercooler, this blockage might only occur externally, on the surface of the fins. But if it’s a liquid-to-air intercooler, the clogging can also happen internally, which can restrict coolant flow. If the blockage is minor, a simple way to fix this is to remove the build-up.

Further on, we will discuss how to perform a cleanout and when to seek assistance if you’re unsure how to perform these fixes. But first, we want to walk you through the cooling system and the general role of the intercooler.

Turbo diesel engines

Turbochargers are often (but not exclusively) found in modern diesel engines to help improve fuel economy and power output. A turbo delivers more intake air than a naturally aspirated engine, allowing for better combustion.

A naturally aspirated engine utilises ambient airflow only. It relies on natural forces such as atmospheric pressure, cylinder movement, and the venturi effect to create a vacuum to deliver the charged air to the combustion chamber.

A turbocharged engine is called a forced induction engine since the air is pushed into the engine under pressure. Being compressed by the turbo, more air enters the combustion chamber. More air means more fuel can be burnt more efficiently to release more energy. More energy = more power.

Compressed air naturally heats up during the compression process. Hot air is less dense and provides less oxygen. This is not ideal for combustion therefore, this hot air must be cooled.

The intercooler cools this compressed air before it enters the engine, which increases oxygen density and helps increase your engine power. The intercooler also assists engine cooling by cooling the air entering the combustion chamber. Without this, your engine’s operating temperature would be higher, which would cause reduced fuel efficiency and accelerated wear.

Signs and symptoms

Now that you know how a turbo diesel system works, we want to help you identify when your intercooler might need some cleaning.

  1. Engine overheating. As we mentioned before, overheating during usual driving conditions is a sure sign that something is wrong. A leak or blockage could reduce the intercooler’s ability to transfer heat.
  2. Noticeable drop in engine power. When the intercooler does not operate correctly, it reduces the efficiency of combustion and power delivery may be reduced.
  3. Increase fuel consumption. The combustion process may be compromised, resulting in increased fuel consumption.
  4. Unnatural smoke coming from the exhaust system. A blocked or damaged intercooler can result in an incorrect air-fuel ratio. Sometimes this can lead to leftover fuel being burnt and black smoke escaping.
  5. Leakage. Sometimes, hoses and lines can collapse, or the coolant (in liquid-to-air intercoolers) can contaminate or leak into the intake airway. You can often tell that this has happened by the above symptoms. If oil builds up inside your intercooler, it may be your turbo leaking. An EGR cooler leak can also contribute to a build-up of deposits inside the intercooler.

To clean or not to clean

intercooler cleaning

It’s possible to tackle intercooler cleanouts yourself, but it’s ideal if you’re familiar with turbocharged systems first. If you feel confident, then following steps will be much easier.

  1. To clean the intercooler, it first needs to be removed from the car. Sometimes this may include removing the front bumper and/or engine cover (depending on where it is mounted).
  2. While removing, be mindful of disconnecting any hoses and piping. Once removed, take off any rubber seals or grommets that may be damaged by cleaning chemicals.
  3. Spray the outside and inlets of the intercooler with a degreaser to prepare any oil and/or debris for removal.
  4. After that, you can rinse the intercooler with acetone, kerosene or even brake cleaner. Place the intercooler in a bucket or plastic container and pour the cleaning liquid through the inlet. Shimmy it slightly and then let it sit for about 15 minutes. Pour it out after this time has passed. You should repeat this step a few times until the cleaning agent comes out clear.
    You can also use methylated spirits to clean the intercooler further as it leaves very little residue.
  5. Rinse out and let the intercooler dry for a few hours before refitting. Take care to dispose of waste chemicals responsibly per your local government’s standards, as they can be toxic (cleaning chemicals may kill grass or other plants).

If a clean-out has not helped your vehicle issues, something more damaging might have occurred. We recommend you take your vehicle to a professional to diagnose underlying issues. Other engine components might also need fixing, so an intercooler clean may not completely solve your problem. If you need a replacement, having a professional install it is good practice.

Talk to a Natrad technician for detailed advice on your next best step. They can advise on replacement or repairs and conduct an intercooler clean-out if you’re uncomfortable doing it yourself.

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