Types of turbo faults and how to detect them

Types of turbo faults and how to detect them


Also known as a turbocharger, a turbo is a type of forced induction system that is commonly used in modern engines to increase their power output and efficiency. A turbo fault can affect performance, efficiency and reliability. 

They use exhaust gases from the engine and send them through a series of moving turbine wheels. This pressurises the air before introducing it into the engine. 

Turbos are an integral part of your car’s engine. They help deliver more power to your drivetrain, improve your car’s fuel efficiency, and reduce your overall emissions – meaning the condition of your car’s turbo will have a significant bearing on its performance.  

If your car is suffering from a loss of engine power, there’s a chance your turbo has a fault. Luckily, there are many different ways to detect different types of turbo faults.  

Read on to learn about some of the most common types of turbo faults, as well as how you can detect them before they become too much of a problem for you and your car. 

Common Turbo Faults & Causes? 

Insufficient engine lubrication 

The oil inside your engine is used to keep its moving parts lubricated and prevent rust and corrosion. The turbo is no exception – with a gas turbine wheel rotating at high speeds, it is essential that the wheel’s bearing remains well lubricated.  

If poor quality or inappropriate oil is used in your car’s engine, the turbo bearings may experience too much friction. Consequently, the turbine won’t be able to rotate properly. This results in insufficient air being delivered to the engine’s cylinders, therefore leading to a reduction in engine power. 

It should be noted that even if you use the right sort of oil, over time it can become contaminated with solid particulates. Similarly, it may evaporate to a point where it’s no longer effective. This is why it’s widely recommended you change your engine oil every 3000 miles or so - dependent on the manufacturer’s recommendations. 

Obstruction due to foreign objects 

If something gets caught in your turbo, it can form a blockage that restricts the flow of gases.  

If your turbo becomes restricted in this way, your engine will be unable to benefit from the pressurised air flow that your turbo is supposed to deliver. Common objects found stuck in turbos include leaves, feathers, and metallic pieces from inside the engine.  

If you notice a significant drop in engine performance, combined with a strange clattering or rattling sound coming from your engine, there’s a chance that something has become lodged in your turbo. 

Lack of pressure in the compressor 

The pressure inside the turbo’s compressor ultimately determines how much air is being forced into the engine. If the pressure is too low, the engine will receive insufficient air, and the power output will suffer.  

Low compressor pressures can be caused by the compressor wheel either not spinning at all, or spinning too slowly. If the compressor wheel isn’t moving, this usually indicates a problem with the bearing inside the turbo.  

However, if the compressor wheel is spinning too slowly, this is likely a result of a blockage in the system, a decrease in engine vacuum, or a problem with the turbo’s wastegate. This type of turbo fault is typically accompanied by significant reductions in engine power or strange engine sounds.  

Exhaust Gas Recirculation (EGR) failure 

The EGR system regulates the amount of exhaust gas that gets sent back into the engine. An EGR system is used in conjunction with a turbo to ensure correct air-fuel ratios are maintained within the engine cylinders. 

If the EGR system isn’t working properly, which is typically caused by sticking in the EGR valves, the engine performance will suffer. If not enough exhaust gas is recirculating into the engine, it may have difficulties starting and poor running, leading to the deposition of carbon in the turbo; dramatically affecting its performance.  

On the other hand, too much exhaust gas recirculating into the engine will lead to the excessive production of nitrogen oxides and coke, leading to significantly reduced engine efficiencies.  

How To Diagnose Turbo Faults 

Loss of engine power 

Normally, you should notice an increase in engine power as soon as you press down on the accelerator. If your car feels unusually sluggish, there’s a good chance a faulty turbo is to blame. Remember, the turbo delivers pressurised air into your engine, so any turbo faults will influence engine power. 

Difficulty accelerating 

Related to a loss of engine power, a faulty turbo will result in difficulty accelerating. Acceleration will feel slower, louder, and your car may judder.  

Blue or black smoke coming from your exhaust 

Blue or black smoke coming from your exhaust is symptomatic of cracks in your turbo’s housing or blown internal seals. These cracks or blown seals will cause oil to leak into your exhaust system, producing distinctive blue or black smoke as it burns off. 

Excessive turbo whistling 

You shouldn’t normally notice any whistling coming from your car’s turbo. If you do hear a significant amount of whistling, it’s likely something’s wrong. In this instance, turbo faults are usually caused by excessive exhaust gas temperatures.  

Fluid leakage from the turbocharger and other areas 

A rusty and carbonized turbo charger

If you notice a significant amount of fluid leakage around your engine, your turbocharger is almost certainly the culprit. Different types of fluids can leak from the turbo. The most common leaks are oil and coolant, though it’s also possible for petrol to leak from the turbo. 

As with blue or black smoke, this is an indication there are cracks or blown seals in the turbo’s housing. 

In conclusion 

A car’s turbocharger is an important part of the engine that helps to improve performance and fuel efficiency, whilst reducing emissions. If your turbocharger isn’t operating properly, you’ll notice reduced engine power, difficulty accelerating, and various other symptoms such as a smoking exhaust or leaking fluid.  

In short, there are many different types of turbo faults, and each can represent a serious problem for your car. 

If you notice any of the issues described in this article, it’s important to take your car to a mechanic for a diagnosis. A turbo replacement can cost upwards of £700, so to make this cost more affordable, split it into monthly payments with Bumper, completely interest-free! 

To apply for a credit limit and see dependable garages in and dealerships in your area, enter your vehicle registration and postcode on our website. 

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