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 some abnormal behaviour, including the obvious one – engine overheating.
So how do you prevent the failure of the all-important intercooler? Well, Natrad has put together a detailed guide on how to spot symptoms and look after your intercooler to avoid costly repairs.
How to clean a turbo diesel intercooler
Sometimes all your intercooler needs is a good cleanout. The heat exchanger works much like a radiator and can sometimes become clogged or blocked. Depending on the type of intercooler, this may be restricted to blockage externally on the surface of the fins. If it’s a liquid-to-air intercooler, the clogging can also happen internally, blocking 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 an intercooler.
Turbo diesel engines
Turbochargers are often (but not exclusively) found in 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 for delivering the charge air through 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 that more fuel can be burnt and also more efficiently to release more energy. More energy = more power.
The difference here is obviously compressed air, which naturally heats up during the compression process. Hot air is less dense and provides less oxygen. This is not ideal for combustion, and so this is where the intercooler comes in.
The intercooler cools the compressed air before entering the engine, which increases oxygen density. Removing this heat caused by compression also assists engine cooling. Without this, the engine operating temperature would be higher, reducing fuel efficiency and accelerating wear.
Signs and symptoms
Now that you know how a turbo diesel system works, we want to help you identify when your intercooler needs some TLC.
- Engine overheating. As we mentioned before, overheating during usual driving conditions is a sure sign that something is wrong. Clogging or blockage could be reducing the intercooler’s ability to transfer heat.
- Noticeable drop in engine power. For the same reason, the engine may not be receiving as much cool air for combustion and power delivery may be reduced.
- Increased fuel consumption. The combustion process may be compromised, which results in increased fuel consumption.
- 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.
- Leakage. Sometimes hoses and lines can collapse or the coolant (in liquid-to-air intercoolers only) has become contaminated. You can often tell that this has happened by the above symptoms. If there is a build-up of oil inside your intercooler, it may be your turbo that is leaking or an EGR cooler leak which could also contribute to a build-up of deposits.
To clean or not to clean
It’s possible to tackle intercooler cleanouts yourself, but it’s ideal if you’re already familiar with turbocharged systems. If you feel confident, then the following steps are made for you.
- 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.
- While removing, be mindful of disconnecting any hoses and piping. Once removed, take off any rubberseals or grommets that may be damaged by cleaning chemicals.
- Spray the outside and inlets of the intercooler with degreaser to prepare any oilor debris for removal.
- 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 once this time has passed. You can repeat this step a few times until the cleaning agent comes out clear.
- You can also use methylated spirits to further clean the intercooler as it acts as a form of degreaser.
- Rinse and let it dry for a few hours before refitting. Take care to dispose of waste chemicals responsibly as they can be toxic. (Disclaimer, it may kill your grass…)
If a clean-out hasn’t made much difference, something more sinister might be happening. We’d recommend you take your vehicle to a professional to diagnose any underlying issues. Other engine components may be malfunctioning, so an intercooler clean may not fully solve the problem. If you need a replacement, having a professional install it correctly is a good idea to achieve optimum performance.
Talk to a Natrad technician for detailed advice on what your next best step is. They can advise on replacement or repairs, as well as conduct an intercooler clean out if you’re not comfortable doing it yourself.