It uses the exhaust gas to drive a turbine. The turbine spins an air compressor that pushes extra air (and oxygen) into the cylinders, allowing them to burn more fuel each second. That's why a turbocharged car can produce more power (which is another way of saying "more energy per second").

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The first signs before turbo failing are:

• Poor Acceleration

One of the most significant symptoms of a failing turbo you should notice is lack of overall power. The car may not accelerate quickly or produce the usual amount of power while on the road. When you are driving a car with a failing turbo, you may notice that your car is slow to respond and does not reach its optimum speeds as rapidly as before.

• Irregular or Excessive Exhaust

An excessive amount of exhaust fumes or grey smoke expelled from the exhaust pipe may be a sign that it is time for a new turbocharger. A crack in the turbo housing can cause oil to leak into the exhaust system, which produces irregular gases.

• Check engine light

In many instances, the engine sensor detects a failing turbocharger, triggering the check engine light on the dashboard. An illuminated check engine light may be an indication that further inspection is necessary to determine whether a repair or replacement of the turbo is required.

• Lack of Boost

Some of the turbochargers, more likely sports cars, have a boost gauge, which displays the amount of boost that the turbo is producing. If your car is one of those, then you can just look at the boost gauge to determine if the turbo is creating the right amount of boost and if it is rising much slower than usual, a replacement turbocharger may be necessary.

• Loud shrieking noise

If a turbo is failing, it may produce a noise when the boost is running. The noise comes directly from the engine and sounds like a loud siren or shriek, which tends to get louder as the problem worsens. Any unusual noise under the car’s bonnet is worth investigating, especially if the sound accompanies any additional turbo failure symptoms.

• Common causes of turbo failure

Some factors can be the cause of a failing turbo, and a thorough examination and diagnostics are often necessary. There are a few common issues that may contribute turbocharger damage and eventually failure.

• Build-up of debris

Small particles or objects, such as rocks or dirt, can enter the turbocharger through the turbine or compressor inlet, especially if the air filter fails to catch debris while the car is in motion. If this occurs, the build-up of debris can cause compressor wheel abrasion or damage the turbine blades, diminishing the performance of the turbo.

• Cracks or faulty seals

Cracks or faulty seals between the engine and the compressor mean that the turbocharger has to put much more effort into building pressure and forcing air into the engine. As a result, the turbo cannot provide its usual level of boost, which hinders its ability to boost the car’s speed and performance.

• Carbon deposits

While clean oil offers the turbo a fresh supply of lubrication, oil that contains an abundance of contaminants can lead to turbo damage. Failing to change the oil or the oil filter regularly can cause the build-up of carbon deposits, which prevents the turbocharger from working correctly.

• Normal wear and tear

Even with proper maintenance and care, a turbocharger endures wear and tear over time. The lifespan of a turbo dramatically depends on the driving habits of the car’s owner, the quality of the turbo part, and the make and model of the vehicle. The typical turbocharger has a lifespan of about 120,000 kilometres (~75000 miles). However, car owners can check the manufacturer’s information to verify how long their turbo may last before it becomes faulty.

my-engine-check.com supplied this information.

Turbochargers allow an engine to burn more fuel and air by packing more into the existing cylinders. The typical boost provided by a turbocharger is 6 to 8 pounds per square inch (psi). Since normal atmospheric pressure is 14.7 psi at sea level, you can see that you are getting about 50% more air into the engine. Therefore, you would expect to get 50% more power. It's not perfectly efficient, so you might get a 30- to 40% improvement instead.

auto.howstuffworks.com supplied this information.

Turbo engines tend to have more problems in many cars, although there are turbocharged engines that are reliable. A turbocharged engine has more components than a naturally-aspirated (non-turbo) motor. A turbocharger itself is not uncommon to fail.

samarins.com supplied this information

refurbish is to rebuild or replenish with all new material; to restore to original (or better) working order and appearance while repair is to restore to good working order, fix, or improve damaged condition.

WikiDiff.com supplied this information

Remanufacturing is the rebuilding of a product to the specifications of the original manufactured product using a combination of reused, repaired and new parts.

vecmar.com supplied this information