This noise is caused by the compressor wheel (and likely the turbine wheel) making contact with the inside of its housing. This should never happen. The wheels are supposed to spin freely on a film of oil at incredibly high speeds (often over 100,000 RPM!), supported by a bearing system. The contact you're hearing is a direct result of excessive shaft play, which is almost always caused by one of the following:
- Insufficient Lubrication: This is the #1 killer of turbochargers. A lack of clean oil, low oil pressure, or a blockage in an oil line can starve the bearings. Without proper lubrication, the bearings wear out almost instantly, leading to the failure you're observing.
- Oil Contamination: If your engine oil is old or contaminated with debris, dirt, or metal shavings, it acts like liquid sandpaper on the bearings, grinding them down and causing excessive clearance.
- Foreign Object Damage (FOD): If a small object like a nut, a piece of a failed air filter, or an engine component gets sucked into the turbo, it can chip or bend the delicate blades of the compressor or turbine wheel. This creates a severe imbalance that destroys the bearings very quickly.
| Possible Cause | Possible Remedy |
|---|---|
| Excessive dirt build up on compressor wheel and/or diffuser vanes | Clean in accordance with details/instructions. |
| Turbocharger damaged | Find and correct cause of failure, repair or replace turbocharger as necessary. |
| Failed diaphragm | Replace using correct actuator service kit. |
| Leaking hose | Replace hose and clips. |
| Wastegate mechanism set incorrectly | Contact engine experts for correct setting details. |
| Restricted compressor intake duct | Remove restriction or replace damaged parts as required. |
| Restricted air duct from compressor to intake manifold | Remove restriction or replace damaged parts as required. |
| Restricted intake manifold | Refer to engine manufacturer's manual and remove restriction. |
| Air leak in feed from air cleaner to compressor | Replace seals, gaskets or tighten fasteners as required. |
| Air leak in feed from compressor to intake manifold | Replace seals, gaskets or tighten fasteners as required. |
| Air leak between intake manifold and engine | Refer to engine manufacturer's manual and replace gaskets or tighten fasteners. |
| Foreign object in exhaust manifold (from engine) | Refer to engine manufacturer's manual and remove obstruction. |
| Restricted exhaust system | Remove restriction or replace damaged parts as required. |
| Exhaust manifold cracked, gaskets blown or missing | Refer to engine manufacturer's manual and replace gaskets or damaged parts. |
| Gas leak at turbine inlet/exhaust manifold joint | Replace gasket or tighten fasteners as required. |
| Gas leak in ducting after turbine outlet | Refer to engine manufacturer's manual and repair leak. |