Turbochargers are delicate components. They spin at over 100 000rpm and operate to incredibly tight tolerances, so have the potential for catastrophic failure.
That said, a well-maintained and healthy turbo should be able to last the life of the engine without any issues. Herewitha few reasons a turbocharger fails, and, more importantly, how you can prevent this from destroying your turbo.
Oil contamination is the biggest killer of turbos, irregular oil changes can cause carbon deposits to form in the oil, these then block the tiny oil ways in the turbo and starve it of sufficient lubrication.
Prevention: The best way to prevent oil contamination is regular servicing and frequent oil changes and the specified service intervals. Good quality oil of the correct grade for the application is a must too, as is cleanliness when any work is carried out to the engine.
Failed exhaust turbine
When the exhaust gases get too hot, as a result of poor engine setup or running, the turbine shaft in the turbo can get so hot it either melts or the turbine wheels can completely separate from the shaft!
Prevention: The only way to avoid this, and other serious engine failures, is to ensure the engine is running correctly at all times.
Impact damage to compressor wheel
With such tight tolerances inside the turbo, and the compressor wheel spinning at over 100 000rpm, any foreign object that is allowed to enter the turbo can cause total destruction in seconds. Even a small piece of debris hitting the compressor wheel will knock things out of balance and an out of balance turbo only has seconds to live!
Prevention: The only route into the compressor wheel is via the air filter, so ensure the air filter is doing its job properly and not allowing any dirt or debris to pass through it .