Melett advices on turbocharger oil contamination

Melett has issued some very useful advice on the growing issue of turbocharger failure, especially in relation to the identification of common failures in warranty situations and to provide advice on how to prevent future failures occurring.

Turbochargers are manufactured to precision tolerances, within 4 microns, and rotate at speeds of up to 360,000rpm. If oil within the turbocharger becomes contaminated this can have severe consequences. Oil is very often overlooked as a critical component, however clean filtered engine oil is a necessity for all turbochargers. Contamination will cause rapid wear to various components and eventually cause catastrophic failure.

Melett says that signs of oil contamination includes, scoring to thrust parts, scoring to journal bearings, scoring to journal bearing diameter of shaft and wheel and the smell of fuel in the oil.

Alternatively, if oil levels are too low or if the wrong grade of oil is used, the turbocharger will also fail. This makes correct oil specification choice essential at every service.

If the original cause of failure is not identified it is likely the same type of failure will occur on the remanufactured turbo. Catastrophic damage to the bearing systems can occur within seconds of the turbocharger commencing operation.

Melett has highlighted many of the common causes of oil contamination. These are;

• If the oil filter is blocked/damaged or a poor quality oil filter is used.
• Excess moisture can lead to premature oil degradation, increased corrosion and increased wear.
• High carbon build up present in the engine can quickly contaminate new oil.
• Accidental contamination of new oil whilst servicing.
• Unchanged oil containing detergent deposits can become very abrasive to the turbo’s precision components.
• Engine wear, which can leave swarf deposits in the oil.
• Degrading oil caused by excessive temperatures or over extended service intervals.
• Internal engine leaks, such as fuel or coolant mixing with oil supply.

To prevent turbo failure Melett recommends using new oil and filters at every service to reduce risk. This oil must be the correct specification and grade for the engine and it should be changed in strict accordance with vehicle manufacturer recommendations. Melett also recommends that filters recommended by the engine manufacturer are used when refitting a turbo and says that replacing or cleaning the oil inlet pipes and in-line micro filters helps to prevent carbon deposits or sludge restricting oil flow to the bearings.

For further information on this or other topics, please contact Melett Technical Support. This email address is being protected from spambots. You need JavaScript enabled to view it.