The turbocharger whistles

The operation of the turbocharger involves pumping the air under pressure into the engine cylinders through narrow air channels. Such a process can hardly be completely silent. A hum or whistle coming from under the hood of a turbocharged car is not uncommon, but sometimes it is the norm, and in other cases – a reason to contact the car service. 

The nature of the whistle 

Normal for a turbocharger is a soft and low sound associated with the movement of air through the pipes. If the whistle under the hood appears at low speed and at low revs, then most likely it is not related to the operation of the turbocharger. The fact that the turbo itself is whistling is usually indicated by a loud and high sound that appears precisely when the speed is set. 

Common causes

The turbo whistles for a number of common reasons:

• depressurization of the system
  
• foreign objects/debris
  
• cracks in the air pipes
  
• damaged intercooler 
  
• wear/damage to the turbo
  

Often, the turbo whistles due to a violation of the tightness of the connections, cracks in the air pipes, poorly fixed clamps and seals. An air leak provokes a whistle, while often there is a noticeable drop in engine power. Additional sound may also occur as a result of debris or foreign objects entering the airway. The air passing through the damaged intercooler can also whistle. If the whistle is accompanied by a change in the colour of the exhaust and increased oil consumption, then there is a possibility that the problem is the failure of the turbo itself (backlash of the impeller, structural wear, etc.) and a thorough diagnosis is required.

Solving the problem 

Not always a whistle under the hood indicates a breakdown of the turbo system. If the sound is loud and high and is accompanied by other symptoms, such as black, blue or white exhaust smoke, engine deterioration or increased oil consumption, then this is a reason to contact specialists. The auto repair shop will be able to determine exactly why the turbo is whistling, if necessary, remove foreign objects from the system, repair or replace damaged elements, check the density of all connections and the serviceability of the turbocharger itself.