Turbo failure : oil contamination
FACT SHEET “The Turbo’s Killer”
This is one of a series of Turbo Failure Fact Sheets from Diesel Levante. Safeguard your reputation and your business – make sure you read them all.
Why does oil contamination 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. Consequently any fault with the oil supply to the turbo means its bearings are likely to fail before the engine’s main bearings.
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 the turbo are clean and clear, so you are certain they can supply uncontaminated oil, at the correct pressure. Contaminated or dirty oil will scratch or score the bearings, leading to rapid wear and ultimately, turbocharger failure.
What causes contaminated oil?
• A blocked, damaged or poor quality oil filter. • High carbon build-up in the engine. This can rapidly contaminate even new oil. • Accidental contamination of new oil during servicing. • A malfunctioning oil filter bypass valve. • Engine wear, leaving swarf deposits in the oil. • Oil that has degraded due to excessive temperatures or extended service intervals
Preventing turbo failure caused by contaminated oil
• Always use fresh oil and new oil filters as recommended by the engine manufacturer when fitting a new turbo. • Ensure the oil is the correct grade for the engine. • Clean or replace oil inlet pipes to eliminate any carbon deposits or sludge that could enter the turbo or restrict oil flow to the bearings