Turbo failure : oil starvation
FACT SHEET “The Turbo’s Killer”
This is one of a series of Turbo Failure Fact Sheets from Diesel Levante.
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Why does oil starvation damage turbos?
As turbochargers can operate at over 6,000 revs per second (360,000 rpm) and endure temperatures of 950°C, turbo bearings are under great stress. The turbine shaft and bearings rotate in a thin film of oil. If oil is not present at start-up and while the turbo is running, the bearings will fail. Running a turbo without oil for five seconds is as harmful as running an engine without oil for five minutes.
While it is important to check the engine oil pressure meets the manufacturer’s specifications, it is even more critical that the oil feed pipes to turbo are clear and clean, so you are certain they can supply oil at the correct pressure.
What causes oil starvation?
• Low engine oil level in the sump. • A bent or kinked oil feed pipe. • Carbon deposits (coking) in the oil feed pipe. • Blockage caused by applying silicone to the oil inlet gasket. • Incorrect oil inlet gasket restricting oil supply. • A blocked, damaged or poor quality oil filter. • Worn oil pump. • Failure to prime the replacement turbo with oil during fitting. • The engine not being used for long periods, particularly in cold weather.
Preventing turbo failure caused by oil starvation:
• Do not use silicone on oil gaskets; it can easily become detached and block oil passages. • Clean or replace oil inlet pipes to eliminate any carbon deposits or sludge that could restrict oil flow to the bearings. • It is important to check the oil pressure and oil supply to the turbo. • Always use fresh oil and new oil filters as recommended by the engine manufacturer when fitting a new turbo.
Extreme heat damage due to lack of oil, the blue colouring indicates excessive temperatures (fig.1 and 2)
Scored and discoloured surfacedue to insufficient oil (fig.3)