Oil leaks in turbochargers can result from various factors, with the most common being incorrect pressure within the compressor and turbine housings. These leaks can lead to catastrophic damage to the bearing system, often occurring within seconds of the turbocharger starting operation.
When properly installed, a turbocharger should not leak oil. However, leaks can still happen in certain situations. Below, we outline the main causes and warning signs of oil leaks.
Examples of what can cause an oil leak:
- Kinked or partially blocked drain pipe
A kink, bend, twist, or partial blockage in the oil return pipe can cause oil pressure to build up within the bearing housing, leading to leaks at both the turbine and compressor ends.
- Overfilled engine oil
An overfilled oil level can restrict proper oil flow, leading to a build-up of pressure in the bearing housing. This excess pressure can cause oil to leak from both the turbine and compressor ends.
When the oil level exceeds the engine manufacturer's specified limit, the crank's motion can also push oil back into the return pipe, restricting flow. This can result in leaks from both the turbine and compressor ends.
- Blow by
The two types of blow by, piston ring and crankcase blow-by, both increase pressure in the crankcase, disrupting the proper oil flow to the turbo. This added pressure restricts the oil return pipe, leading to oil leaks at either the turbine or compressor end of the turbocharger.
Did you know?
Oil leaks can also occur when engines are idling.
Lower pressure within the housings can create a vacuum, allowing oil to seep into the turbine housing. Once the engine reaches normal operating speeds, the pressure stabilizes, and the leaks typically stop.
A quick list of causes:
- Old turbo core
- Incorrectly fitted oil flange gasket
- Excessively high oil pressure
- Physical damage to the turbo’s rotating parts and excessive bearing clearance (possibly caused by another failure)
- Excessive crank case pressure (blow-by from worn piston rings/bores)
- Re-used or damaged oil return pipes
- Over filling of the oil
- Use of silicon sealant / incorrect gasket