Turbochargers

How a turbocharger works

A turbocharger increases engine power. Exhaust gases drive a turbine, and on the same shaft sits a compressor that forces intake air into the cylinders.

More air with a matched amount of fuel gives more power, more torque and better efficiency. Turbochargers are fitted to petrol and diesel engines, both four-stroke and two-stroke.

Variable geometry turbochargers have movable vanes on the turbine side. They change the flow of exhaust gas, so the turbo works well at both low and high revs.

Signs of turbo failure

• loss of power and slower engine response
• blue or black smoke from the exhaust
• whistling or whining that was not there before
• oil in the intake pipe or the intercooler
• shaft play or damaged blades

A turbo most often fails because of lubrication: dirty or old oil, a weak oil supply, or shutting down a hot engine right after work. Before fitting a new turbo, check the oil feed and return and the air filter, otherwise the new turbo fails for the same reason.

What to send in an enquiry

• the number from the turbocharger plate (the turbo manufacturer's number)
• the engine manufacturer's catalogue number, if it is on the plate
• the make and model of the engine and of the machine or vehicle
• the engine serial number
• a photo of the plate

If the plate is illegible, send photos of the turbo from all sides and the engine details. More on this in the guide How to find the right spare part.