TURBOCHARGER FACTS

The average temperature of the exhaust gas at the entry point to a diesel turbo is 800°C, a petrol engine turbo can reach 1000°C which is hot enough to melt window glass.

 

At average engine revs a medium size turbo will swallow 130 cubic feet of air per minute, this is the equivalent to the interior volume of a Ford Transit van. 

The turbine blades in a turbo are made from a high nickel alloy as used in jet aircraft engines, a blade will travel in the region 850mph and the exhaust gas entering it will be supersonic.

 

The air entering the compressor impeller of the turbocharger on a petrol vehicle can be travelling at a speed close to Mach 1 (767mph). 

 

Piston blow-by and the resulting crankcase/sump pressure if not vented off adequately is the most common cause of turbocharger oil leakage. 

If the engines oil pressure is low the turbocharger will be the first engine component to fail. Dirty oil, low-quality oil and even the wrong viscosity oil can also cause the turbo to fail.

 

New generation turbocharger impellers rotate at up to 220,000rpm, the impellers on a Boeing 747 engine rotate at around 7,000rpm in comparison. 

Turbo balance is crucial, a 2kg force is acceptable. We often find turbos supplied for a service with 6 kilos of imbalance, this is equivalent to driving with a house brick attached to your car wheel.

 

Fully synthetic oils and mineral oils do not mix as it dilutes or suppresses the superior properties of the synthetic oils.  In severe cases, they can coagulate.

 

The most common contaminants found in the oil are 'free-floating' carbon deposits, fuel and the by-products of combustion.