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Turbo Failure

Turbo Failure

What causes oil contamination?
  • If the oil filter is blocked/damaged or a poor quality oil filter is used
  • Excess moisture can lead to premature oil degradation
  • High carbon build up in the engine can quickly contaminate new oil

Alternatively, if oil levels are too low or if the wrong grade of oil is used, the turbocharger can prematurely fail.

Turbo failure prevention:
  • Using new oil and filters helps to reduce the risk
  • Replacement oil must be the correct grade for the engine
  • Replacing or cleaning the oil inlet pipes and in-line micro filters
Signs of oil contamination:

Turbo Oil Contamination

Scoring to the journal bearing diameter of the shaft

Turbo Oil Contamination

Scoring to thrust parts

Turbo Oil Contamination

Scoring to journal bearings

What causes overspeeding?
  • Poor boost control in the ECU software (bad tuning)
  • Over-fuelling which then causes boost creep at higher RPMs
  • Inconsistent flow of air into the turbo - this can be caused by a hole in the air hose or it becoming completely detached, or by restrictions in the air intake filter or pipe work
  • Intercooler pipework leaks - The Pressure sensor is AFTER the Intercooler
  • The wastegate or VNT mechanism has been set incorrectly
  • Worn injectors
  • Installing an incorrect turbo
  • Loss of signal to the SREA (Simple Rotary Electronic Actuator) for the wastegate or VNT control
Signs of overspeeding:

Turbo Overspeed

Complete component failure

Turbo Overspeed

Orange peel effect to compressor wheel

Turbo Overspeed

Compressor wheel rubs

What causes of a lack of lubrication or oil starvation?
  • Poor oil filter maintenance
  • Insufficient oil in the sump
  • Incorrect oil inlet gasket used, leading to restriction in oil supply
  • A damaged, blocked or low quality oil filter
Turbo failure prevention:
  • Turbo oil supply 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
Signs of oil starvation:

Turbo Oil Starvation

Material transfer from journal bearing

Turbo Oil Starvation

Discolouration to the journal bearing diameter of the shaft

Turbo Oil Starvation

Excessive wear to thrust bearing

Signs of foreign object damage:
  • Chipping of compressor or turbine blades
  • Pitting around the compressor inlet
What causes foreign object damage?
  • If the air filter is damaged (or faulty), of a low quality or missing, objects will be sucked into the air intake
  • Debris from a previous turbocharger failure
  • Broken engine components e.g valves or injector tips
Turbo failure prevention:
  • Ensure no debris or engine fragments remain from the previous turbo failure
  • Using new gaskets helps to prevent the possibility of gasket break up and also ensure a perfect seal
  • Make sure air hoses are clear from blockages or loose objects
Turbo Overspeed
Damage to inducer of compressor wheel
Turbo Overspeed
Damage to inducer of turbine wheel

Signs of oil leaks:
  • Blue smoke from the exhaust
  • Oil residue in compressor/turbine housings
Causes of oil leaks at the compressor end:
  • Blockages or restrictions to the air intake pipe, hose or air intake filter can create a vacuum, causing oil to leak into the compressor housing
  • Air leaks in the intake hoses or at the intercooler
Causes of oil leaks at the turbine end:
  • Leaks within the exhaust system
  • A clogged bearing housing
  • Leaks in the EGR (exhaust gas recirculation) system
Turbo Oil Leaks
Causes of oil leaks into the compressor and turbine ends:
  • Repeated hot engine shutdowns leading to carbon deposits (coke) in the centre housing
  • Physical damage to the turbo’s rotating parts and excessive bearing clearance
  • Fitting the incorrect turbocharger
  • Restrictions in the oil return pipe
Turbo failure prevention:
  • Ensure air and oil drain systems are clear from blockages or restrictions
  • Check the exhaust system to make sure there are no leaks present
  • Ensure DPF and Catalytic converter are free of blockages
Turbo Oil Leaks
Thanks to Melett for all the detail for this blog post.

We can supply their full range of Replacement Turbochargers, as well as a HUGE range of spare parts for most Turbo Manufacturers. You can view the listed products HERE

And when it all goes very wrong, you might see a failure like this (massive overspeed)

22 09 2018

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