Diagnosing Issues With a Turbo Before Failure

Most of the time when a turbo begins to fail there are some pretty noticeable signs but what are they?Turbochargers are very simple but complicated parts, basically just an air pump. Turbo units work by using the exhaust pressure to spin the blades on the exhaust side and in turn that spins the intake blades. While that may seem simple it takes some serious engineering to make it work perfect. The signs and causes of turbo failure are easy to catch if you know what to looks for.

Failure and Cause:

A turbo begins to burn oil:

Bad seals in the housing or too much pressure inside the oil system can be a common issue. When the seals in a turbo are low quality or have worn out over time they will begin to allow the oil to pass through and be pulled into the engine. High pressure inside the oil system in a car can also cause oil leakage, the pressure must go somewhere and the seals in the turbo are usually the first to go.

The vehicle is making no Horsepower:

There are a number of reasons this can happen but we will concentrate on the turbo related issues. I boost leak would be the first, any space where air can escape from the pressurized part of the intake is considered a boost leak. This will cause the vehicle to mix too much fuel since some of the air that was expected is not getting to the cylinders.

Too much back pressure can also kill horse power and can usually be caused by some sort of blockage (yes the old banana in the tailpipe) impeding the flow of exhaust gasses. The air has to go somewhere and it will usually stall the motor or blow out the seals on the exhaust side of the turbo. This is very dangerous to the motor.

The Turbo is whining under boost:

Whining can be caused by oil starvation or boost leaks, which can sometimes be mixed up.  Hope for the latter since a boost leak is simple to fix. Oil starvation will cause whining since the bearings are grinding against each other and metal on metal is not a good sound. This sound also means that your turbo is on its last legs and you need to stop the car. Turbo bearings can only last a few minutes at best without proper oil flow. Not only do the bearings need to stay lubricated but they also use the oil for cooling in many cases.

Many a mechanic will just tell you the turbo is bad to make a sale on parts that are not needed, so know your questions when you arrive. If someone says the turbo is bad ask why, protect yourself by knowing why it failed. When you know what the real issue is you can keep it from happening again, you might even be able to save thousands since the only real problem was a $3 seal instead of a $3000 repair. If you don’t know people will take advantage so be sure you are the one in control of your car, on the road and on the lift.