mechanic fixing intercooler

Everything you need to know about intercoolers

Intercoolers, found in turbo or supercharger engines, provide much-needed cooling that a single radiator can’t. Before we explain how they work, we’ll explain why you might need one.

For the sake of simplicity, we’ll stick to engines that use turbochargers as an example. Turbocharged engines produce a lot of heat while compressing air, a process that helps to squeeze as much air as possible into the engine.

More air equals more power (among various other benefits such as fuel efficiency and reduced waste). That may sound simple enough, but compressed air gets very hot which means it loses density and therefore, oxygen.

Oxygen is vital as it is what aids combustion within the fuel and air mixture. To make use of the compressed air, it needs to be cooled to increase density and oxygen — this is where the intercooler comes in.

Natrad has a large range of intercoolers for performance vehicles or engines that need a little extra ‘oomph’. Get in touch with us for expert advice and fantastic service.

From hot to cold

A forced induction engine is not uncommon in high performance vehicle applications. It has a range of benefits while remaining light-weight, which is a big bonus, particularly for racing.

However, all that compressed air can get to over 205 ° C in extreme conditions. As we mentioned before, hot compressed air isn’t great for combustion. That’s where an intercooler comes in.

The intercooler aids this process by cooling the air down before it enters the engine and combustion chamber. Depending on what kind of intercooler it is, the cooling process may be a little different.

Types of intercoolers

An intercooler is a heat exchanger, and — much like a radiator — it processes air through fins and cools it down. There are two main types of intercoolers:

  1. Air to air intercooler

This is the most common application for everyday vehicles as it’s a very simple system where is processed by:

  • Entering the turbocharger air intake
  • Changing into hot compressed air
  • Passing by the intercooler and cooling down before being sent to the engine

It usually relies on ambient airflow from the front of the car to flow through the intercooler and cool the compressed air down, much like a radiator.

Main benefits:

  • No liquid leaks
  • Light-weight
  • Simple system
  • Cost-effective
  • Unlikely to experience heat soak if there is good airflow
  1. Liquid to air intercooler

A liquid to air intercooler is far more complex, but they are becoming increasingly popular in cars these days due to higher efficiency. The process works like this:

  • Cool air enters turbocharger intake
  • Turbocharger compresses and heats air
  • Heated air is sent to the intercooler which cools it down before it is sent to the engine
  • At the same time, coolant is also circulating through the intercooler
  • The hot coolant is circulated to the radiator which sends cold coolant back to the intercooler to aid in further cooling

Given there are two circuits carrying air or coolant, this usually requires more accessories and fittings such as hoses. As such, it can be a little on the expensive side, but is still a highly effective system — particularly in applications like drag racing vehicles.

One potential problem includes the risk of heat soak, where there is a build-up of residual heat near the engine and not enough cooling ability to reduce the temperature.

This can generally be solved by letting the car run for a period of time before turning off the engine, to allow the cooling system to continue working.

Main benefits:

  • Highly efficient
  • Efficiency can be exaggerated by using ice or other chemicals for short amounts of time
  • Less turbo lag
  • Can be placed anywhere in the engine bay
  • Shorter routing

Common intercooler faults

As discussed above, there a few things to watch out for with intercoolers. Luckily, most of these are easy fixes, but it’s not hard to fit a replacement should you need it. Common intercooler faults include (but are not limited to):

  • Leaking hoses (if liquid is involved)
  • Failure due to impact damage
  • Installation issues leading to malfunction
  • Overheating or heat soak (due to bad intercooler placement and reliant on ambient airflow)
  • Oil contamination from leaks into the system
  • Clogging

Signs and symptoms

  • Noticeable drop in engine power
  • Increased fuel consumption
  • Unnatural smoke from the exhaust system
  • Noticeable coolant leakage (which could indicate other problems such as radiator failure)

If you’re looking to repair your intercooler, Natrad workshops across Australia can help. If repairing is not a sustainable option, Natrad also has a range of intercooler parts or custom made alternatives.