What Kills a Turbocharger in a Diesel Engine?

A turbocharger is a critical component in a diesel engine, but several factors can cause it to fail prematurely. Understanding these issues can help prevent costly repairs and extend the life of your turbo.

One of the biggest threats to a turbo is poor lubrication. The turbo relies on a steady supply of clean oil to keep its bearings cool and reduce friction. If the oil level is low, dirty, or contaminated, the turbo can suffer severe damage. If its supply is restricted, even momentarily, it can cause catastrophic damage to the bearing systems, destroying a turbo within a matter of seconds, and in severe cases, the engine.

Foreign objects entering the turbo can destroy it quickly. Today's modern turbos spin at speeds over 300,000 rpm and endure temperatures close to 1,000°C. In these conditions, even the smallest of particles sucked into the turbine, compressor or bearing housing can result in immediate turbo failure. Worse still, these same fragments can be carried into the combustion chamber, causing irreversible damage to the engine too.

Running the turbo at excessive speeds is another common killer. Each turbo is designed and manufactured to rotate at the correct speed for its application. Over speeding is when the turbo rotates at a greater speed than its operational limits. Over speeding can push the turbo beyond its safe operating parameters, causing it to fail by damaging the turbine or compressor wheels and bearings. If the turbo continues to over speed, it can over boost the engine, resulting in serious damage to the internal components and potentially complete engine failure.

Carbon build-up is a silent turbo killer. The main culprit of carbon deposits is driving style, stop-start driving, extended engine idling and a frugal driving style can all prevent the engine from reaching temperatures that burn off deposits. Carbon can restrict airflow, cause imbalances, and ultimately lead to turbo failure.