Below we have highlighted the causes and the signs of oil starvation, to help you identify and prevent oil starvation from reoccurring when carrying out a repair. If the original cause of failure is not identified it is likely the same type of failure will occur on the remanufactured turbo.
A lack of lubrication can result in catastrophic damage to the bearing systems which can occur within seconds of the turbocharger commencing operation. Quite simply:
- If oil levels are too low, the turbocharger will fail;
- If the wrong grade of oil is used, the turbocharger will fail;
- If oil becomes contaminated, the turbocharger will fail.
Signs of lack of lubrication / oil starvation:
- Material transfer (caused by high temperature due to friction from bearings) to other thrust parts and the journal bearing diameter of the shaft and wheel;
- Discolouration to the thrust parts and the journal bearing diameter of the shaft and wheel;
- Excessive wear to the thrust pads of the thrust bearing;
- Excessive wear to the journal bearings.
Causes of lack of lubrication / oil starvation:
- Poor oil filter maintenance;
- Insufficient oil in the sump;
- Incorrect oil inlet gasket used leading to restriction in oil supply;
- Build-up (coking) / carbon deposits in the oil feed pipe;
- Applying silicone to the oil inlet gasket causing blockages;
- Sludge or coke build up in bearing housing from hot shutdowns;
- A damaged, blocked or low quality oil filter;
- Failure to prime the turbo with oil before initial run;
- Engine left idle for long periods, especially during cold weather;
- Oil feed pipes containing bends or kinks;
- Engine wear.
Preventing turbo failure caused by lack of lubrication / oil starvation:
- Oil supply to the turbo is critical, always check oil pressures are correct;
- Avoid using silicone on oil gaskets as they can easily become detached and block oil passages;
- Clean or replace oil inlet pipes to remove carbon deposits or sludge that could restrict oil flow to the bearing systems;
- Use fresh oil and new oil filters (which have been recommended by the engine manufacturer) when fitting a replacement turbocharger.