Expert advice

Recognising the symptoms of a failing turbo

Certain signs can indicate that the turbo is malfunctioning.

• Loss of power. A noticeable drop in the vehicle’s performance, particularly when accelerating, may be linked to a boost problem. The engine may feel less responsive or struggle to rev up.
• Whistling or unusual noise. Abnormal whistling, a metallic noise or a change in the turbo’s usual sound may reveal wear or a mechanical defect. A slight whistle can be normal on some vehicles, but any new or unusual noise is worth checking.
• Excessive exhaust smoke. Blue, black or abnormally heavy smoke can have several causes. In some cases, it may be linked to a turbo problem, particularly faulty sealing or oil getting through.
• Abnormal oil consumption. A rapid drop in the oil level or unusual consumption may be a sign of a fault. It is important to check the oil level regularly to avoid further damage.
• Engine warning light or limp mode. A fault in the boost system can cause the engine warning light to come on or the vehicle to switch to limp mode. An electronic diagnosis can then identify the source of the fault more precisely.

Why can a turbo fail?

A turbo failure is not always caused by the turbo itself. Before any replacement, it is essential to find the source of the problem so that a new turbo is not damaged in turn.

• Lack of lubrication. The turbo runs at very high speed and requires constant lubrication. A lack of oil, unsuitable oil, insufficient pressure or a blocked line can cause rapid wear of the internal components.
• Contaminated oil. Oil laden with impurities can damage the turbo’s bearings and moving parts. Following the oil change intervals and using an oil suited to the engine are therefore essential.
• Foreign objects. A foreign object can enter the turbo through the intake or the exhaust and damage the compressor or turbine wheel blades. This can cause a loss of efficiency, vibration or mechanical failure.
• Air intake problem. A clogged air filter, a damaged hose or a leak in the intake system can disrupt the turbo’s operation.
• Exhaust system problem. A blocked particulate filter, catalytic converter or other exhaust component can create excessive back-pressure and damage the turbo.
• Improper use or insufficient maintenance. Oil changes spaced too far apart, unsuitable oil or repeatedly switching off the engine immediately after hard use can help shorten the turbo’s service life.

Before replacing your turbo

Replacing a turbo should not be limited to removing the old part and fitting the new one. It is important to identify and correct the cause of the failure.

Before fitting, be sure in particular to check:

• the lubrication system
• the oil feed and oil return
• the quality and level of the engine oil
• the oil filter
• the air filter
• the intake hoses
• the intercooler
• the exhaust system
• the particulate filter or catalytic converter, if the vehicle has one
• that there are no foreign objects in the ducts

Depending on the vehicle and the fault found, other checks may be necessary.

After replacing the turbo

The first few minutes of running after the turbo has been replaced are important.

• Prime the lubrication correctly. Before the first start, it is essential that the turbo is properly lubricated following the procedure appropriate to the vehicle. Starting without sufficient lubrication can damage the turbo very quickly.
• Check for leaks. After fitting, check in particular the oil connections, air hoses, clamps and gaskets, and look for any oil or air leaks.
• Let the engine run in gradually. After installation, it is advisable to avoid hard acceleration straight away. The engine and turbo should reach their operating temperature gradually.
• Carry out a follow-up check. After the first few kilometres, a visual inspection can help detect a leak, a loose hose or any other anomaly.

How do you identify your turbo’s part number?

The turbo’s part number is one of the most important pieces of information for correctly identifying the part compatible with your vehicle. It is usually found directly on the turbo.

Where can you find the part number?

Depending on the make and model, the part number may be shown:

• on a metal plate
• on a label
• engraved directly on the housing
• on a small plate attached to the turbo

The part number may consist of numbers, letters or a combination of both.

Examples of common brands

Depending on your vehicle, you may come across turbos from manufacturers such as Garrett, BorgWarner, KKK, Mitsubishi or IHI. Each manufacturer uses its own part numbering system.

Why is the part number important?

Two very similar vehicles may use different turbos. The make, model, year or engine are therefore not always enough to guarantee compatibility. Whenever possible, always give TXF Turbo:

• the part number shown on the turbo
• the vehicle’s registration number
• the model
• the engine
• the year of the vehicle

This makes it easier to identify the right part.

Our advice for extending your turbo’s service life

A few good habits can help protect the turbo and the engine.

• Keep up with oil changes. Change the oil according to the manufacturer’s recommendations and use an oil that meets the specifications intended for your engine.
• Replace the filters. The oil filter and air filter play an important role in protecting the engine and the turbo. Filters in poor condition can encourage wear or let impurities in.
• Monitor the oil level. Check the engine oil level regularly. An insufficient level can lead to poor lubrication of the turbo.
• Warm the engine up gradually. When the engine is cold, avoid hard acceleration. Give the oil time to reach a suitable temperature and circulation.
• Avoid switching off immediately after hard use. After a demanding journey or heavy load on the engine, it may be preferable to let the engine settle back to calmer running before switching it off. This helps limit thermal stress.
• Do not ignore the first symptoms. A loss of power, unusual smoke or a new noise should not be ignored. A prompt check can help identify a problem before it leads to more serious damage.

Faulty turbo: repair or replace?

It depends on the condition of the part and the nature of the fault. In some cases, a repair may be possible. In other situations, replacement with a remanufactured turbo or another solution may be more suitable.

The diagnosis makes it possible to determine the most appropriate solution based on:

• the overall condition of the turbo
• the damaged components
• the part number
• the type of fault
• whether a repair is technically feasible

TXF Turbo can help you identify what you need.

Mistakes to avoid

To limit the risk of another failure, avoid in particular:

• replacing the turbo without looking for the cause of the failure
• reusing old or contaminated oil
• neglecting to replace the filters
• fitting a turbo without checking the oil lines
• leaving impurities in the intake system
• putting heavy load on the engine immediately after fitting
• using an approximate turbo part number without checking it