Troubleshooting can be a daunting task for the average diesel owner, given the complexity of modern engine technology. But with a little understanding of how systems work, and what a functioning engine looks and sounds like, it’s not difficult to identify potential problems before they become expensive ones. Turbochargers, for instance, are generally only going to fail due to some form of mechanical damage or physical restriction, such as a blockage from debris. So it’s advisable to look for other likely culprits when failures other than these present themselves. The following is a useful checklist to help you troubleshoot failures in your turbocharger and locate their potential causes:

Excess Smoke

If you see excessive smoke coming from your turbo, look for restrictions around your intake, dirty air filter, seal or gasket leaks; inspect for cracks in the exhaust manifold.

Engine Runs Hot

Check for leaking hoses, seized valves, restrictions to air flow at compressor intake. Check air filter. Excessive heat can also be the result of incorrectly fuel injectors or injector pump. Check manufacturer documentation for proper settings.

Engine Lacks Power

In addition to a potentially damaged turbo unit, other possible causes for loss of engine power include incorrect valve timing, burnt valves or pistons; air leak between compressor and intake manifold, or intake manifold and engine. Check also for restrictions, foreign object blockage or leaks in exhaust system.

High/Excessive Oil Consumption

Check for: restrictions in turbocharger oil drain line or crankcase breather; worn piston rings, dirt build-up on impellers. Look for coking, or sludge build-up in turbo bearing housing.

Noisy Turbocharger

If the turbocharger is operating at a higher than normal noise level, or whistling, there are several possible causes, apart from damage to the turbo unit itself, most often some form of either air leak or restriction. Check for restrictions, leaks, or blockages as previously described, focusing first on the intake area, then look for blockages or cracks in the exhaust.