What happens when a turbocharger fails?

[ORosalie]

Several common symptoms of turbocharger failure are as follows: 1. Oil leakage. This usually occurs when the shaft seal of the turbocharger's exhaust-driven shaft is damaged, allowing engine oil to enter the fresh air intake and subsequently the engine cylinders. Upon disassembly, the shaft will be found covered with carbon deposits, which are residues from burnt oil. 2. Turbocharger issues caused by oil system problems. For example, a failed oil filter allows contaminated oil to enter the system. The turbocharger shaft, spinning at hundreds of thousands of RPM, relies on precise clearance fits for its seals, making it a highly precision component. 3. Problems caused by intake issues. For instance, a damaged air filter allows large particles to enter the air passage, damaging the impeller at high speeds. 4. Mechanical issues with the turbocharger itself. Primarily involving the pressure relief valve (also called the wastegate), which is a one-way air valve that opens when internal pressure becomes too high. If this valve fails, strong engine vibrations can be immediately felt during high RPM operation.