Common Problems

Common Problems

As a general rule turbos don’t just fail there is usually an underlying issue, the top 5 contributing factors to a turbo failing are:

  • Foreign objects

  • Faulty or split intercooler

  • Faulty or split intercooler hose

  • Engine related conditions

  • Interruption or restriction to oil supply

Turbos are quiet often blamed for many vehicle issues such as leaking oil, noisy or squealing sounds, low vehicle power.

Some common issues that are often misdiagnosed to be turbo at fault:

Turbo Leaking Oil – A small amount of oil in the turbocharger is present from when the vehicle is brand new and is not always an issue with your turbocharger.

Noisy or Squealing Turbo – If the noise/squeal comes and goes and is noisier at higher revs and quietens when backed off  this will usually be an air pressure or exhaust pressure leak not a turbo problem. If the noise / squeal is constant that is when you might have turbo issues.

Low Power – Many times low vehicle power can be assumed to be caused by low boost however many factors can cause low power in your vehicle. It is best to have your vehicle checked over by someone equipped to diagnose fuel injection and turbo issues to make sure you are in fact replacing or repairing the right part to rectify your low power issue.

Need some advice before you make a decision give us a freecall on 1300 305 359!


  • Are non-genuine turbo parts really an option?

    Are non-genuine turbo parts really an option?

    Everyone wants to save a buck but are non-genuine parts really an option?


    You send your turbo into the local turbo repair specialist who is able to repair your turbo, no problems, but uses non – genuine parts for a much cheaper repair.

    Sounds great! Right? More money in your back pocket means more money for the next project!

    Unfortunately this is generally not the case.

    Turbo failure due to using non-genuine parts.

    Turbo failure due to using non-genuine parts.

    Using non – genuine parts in a repair can result in your vehicle having:

    • Poor performance
    • Low boost
    • Poorer fuel economy
    • Premature failure of the turbo
    • Engine failure

    Saving a few bucks on your turbo repair only to have your vehicle break down as a result of inferior parts used in a repair can have you spending big bucks in the long run. Some of the costs can include:

    • Paying for a tow truck
    • Being without your vehicle for unknown period of time
    • Replacement of not only your turbo but potentially intercooler (or engine) if the turbo fails and fractured pieces of the compressor wheel shoot into the inlet manifold.

    Are you getting what you paid for with your turbo repair?

    It’s worth asking the question when your repair is being quoted to save a lot of time and frustration down the track.

    Having your turbo repaired using only genuine parts ensures that the turbocharger meets the original specifications.

  • Turbo Failure Ford Falcon

    Such an easy check can prevent your Ford Falcon turbo failing.

    There is an inline filter in the oil supply pipe to the turbo in a Ford Falcon (located in the fitting which screws into the block).

    This filter is often forgotten about during servicing of the vehicle.

    If it is not regularly checked / cleaned / replaced it can block up, restricting oil flow to the turbocharger which will inevitably lead to premature turbocharger failure from insufficient lubrication to the bearing cage.

    ford logo

    The inline filter is a genuine Ford part and can be sourced from your local Ford dealer.

    The genuine Part number for the turbo inline filter in a falcon BA / BF is : SY9P424A

  • Nissan Patrol ZD30 ETi Turbo Service Bulletin

    Nissan Patrol ZD30 ETi Turbo Service Bulletin

    Nissan Patrol ZD30ETi


    PART NO: 724639-5006 / 724639-0006 / 724639-5006S

    OEM PART NO: 14411-VC100 / 14411-VC200 / 14411-2X900 / 14411-2X90A / 14411-VB100

    Before replacement of this turbocharger the following information should be taken into consideration

    Turbocharger failures are generally the result of external influences and there have been instances of recurring turbocharger failures for this application. In some circumstances the turbocharger can overspeed and cause excessive boost (or a boost spike), and the vehicle will temporarily go into limp home mode. The overspeed of the turbocharger can be caused by, but not limited to a low signal voltage from the air flow sensor.

    It is recommended to insure that the air mass voltage is checked and is within the manufacturers’ specification. If the air mass sensor is not operating correctly and the vehicle continues to be driven, it can cause premature turbocharger failure.

    The engines lubrication and engine management system must also be checked to eliminate further possible causes of recurring turbocharger failure. If the initial turbocharger failure is unknown it should be assessed by a turbocharger technician prior to fitment of the replacement unit.

    As the above failures are caused by external factors outside of the manufacturer or suppliers control, any failures resulting from the above conditions will not be considered for warranty.

  • 53039880145 Hyunda Iload Turbo 28200-4a480

    Recurring turbo failure for Hyundai ILoad & IMax

    Recurring Turbo failures for Hyundai ILoad and IMax

    Turbo Part Number: 53039880145 / 53039700145 
    OEM Part Number: 28200-4A480 

     Service Bulletin

     Prior to fitment of the replacement genuine turbocharger it is important to determine the original cause of failure to prevent reoccurring turbocharger failures.

    As per the technical service bulletin SE07812 the following must be inspected to assist with the diagnosis of the root cause.


    1. Inspect turbocharger for any damage
    • Excessive shaft radial & axial play or damage to the rotor assembly blades
    • Bent and/or broken shaft
    • Carbon build up within the nozzle ring assembly (inside VGT system)


    1. Inspect intercooler assembly
    • Inspect for split fins with oil contamination


    1. Inspect oil pick-up screen
    • Inspect screen for carbon blockage


    1. Inspect injectors
    • Inspect for evidence of leaking washers and carbon build-up around outside of the injector body


    1. Inspect the injector seat in cylinder head for damage


    The above conditions may result in combustion gases entering the engines crankcase resulting in excessive blow-by and carbonising/thickening of engine oil.


    Note: Poor vehicle servicing or incorrect engine oil specifications can also result in the above failures and should not be confused with poor injector sealing as the root cause.



    If injectors have been leaking compression past sealing washer (resulting in carbon contamination in oil and blockage of oil pick-up), the injector holes within the cylinder head will need to be cleaned of any carbon build-up to ensure sealing integrity and the injector washers will need to be replaced. Failure to remove all carbon deposits from the injector holes will result in repeat blow-by. Injector clamp bolts need to be replaced with new bolts and ensure the torque is set to specification.

    Note: Engine oil and oil filter must be replaced if compression has leaked past the injectors.



    Combustion gases entering the engines crankcase, poor servicing of the vehicle or incorrect grades of oil can result in a number of ensuing issues with the turbocharger;

    • A reduction of oil quality to the turbocharger causing premature bearing and shaft wear, and potentially shaft fracture
    • Insufficient or interrupted supply of oil to the turbocharger causing premature bearing and shaft wear, and potentially shaft fracture


    Split silicone hoses between the turbocharger, intercooler and inlet manifold (and/or intercooler leaks) can also allow the turbocharger to overspeed. This is due to the turbo ‘over working’ to overcome the loss of boost pressure due to the pressure leaks. Overspeed failures result in compressor wheel fatigue (loss of a blade, or complete fracture) with secondary failures such as shaft fracture.


    Denco Diesel & Turbo can also assist with turbocharger failure analysis (if the above diagnosis points are unable to be determined) by disassembling the original failed turbo for internal inspection. While not completely conclusive (some turbocharger failures are so catastrophic that root cause is difficult to ascertain), it can be helpful in finding the original fault or in the very least point you in the right direction.


  • Turbo failed twice – find out why!


    A customer called last month looking to replace a turbo for one of their customers, we supplied them with a brand new GENUINE Holset turbocharger which they onsold to their customer.

    This turbo also failed.

    As a general rule turbos don’t just fail – there is usually an underlying issue, split intercooler or  hoses, oil restriction or an existing engine condition. A lot of the time the turbo is the first to cop the blame but more often than not it is not a turbo issue.

    Our customer requested a new turbo again before having the first turbo assessed to see why it had failed, their customer requested this as they could not afford any downtime, however another BRAND NEW GENUINE TURBO failed immediately.

    Extra costs and more time off the road.

    This immediately rang alarm bells to us – there must be an existing condition that caused both these turbos to fail identically.

    Upon inspection of the second failed turbocharger we found the parts to be heat effected from an interrupted or restricted oil supply.

    • heat effect turbo thrust bearing
      Carbonised oil on Thrust Bearing due to interruped oil supply.
    • beat effect turbo thrust bearings
      Turbo Journal bearings – excessive heat damage caused by interrupted oil supply
    • Restricted oil flow on a turbo
      Interrupted Oil Flow Damage on a HX50 Holset Turbo

    Due to the fact the first turbocharger failure was not diagnosed the second turbo failed identically to the first.



  • My Turbo is leaking oil

    We receive so many calls from our customers –

    “I need a replacement turbocharger mine is leaking oil”


    A small amount of oil in the turbocharger is present from when the vehicle is brand new and is not always an issue with your turbocharger.

    Don’t forget, a small amount of oil can look like a lot of oil – check that you are using oil on your dipstick BEFORE you go replacing your turbo unneccessarily.

    Turbo leaking oil from Compressor side

    Possible causes of leaking oil could be: Engine Breather

    The turbocharger pulls an oil vapour from the crank case ventilator into the air intake tube between the air cleaner and the turbocharger. When this vapour cools and/or when it goes through the turbocharger the oil content is seperated and reduced back to a liquid which leaves a small amount of oil residue on the compressor side (cold side) of the turbocharger.

    It is much the same concept as a boiling kettle. When the steam vapour cools it is reduced to water.

    This is what is happening with your oil vapour and as a result you are seeing oil residue on your turbocharger.

    This small amount of oil residue is present right from the time that the vehicle is brand new. It is usually not noticed until the vehicle becomes older and the rubber connections and hoses become a little bit harder, the oil then begins to weep around the connections.
    It is often only a tablespoon of oil but because of the nature of oil it can look like a lot.
    If the turbo was genuinely faulty and was using as much oil as it appears this would be evident on the dip stick. If your vehicle is not using excessive amounts of oil then it is most likely that there is no cause for concern with your turbocharger.If you are still unsure as to whether your turbo might be faulty you can FREECALL 1300 305 359 here and we would be happy to go through it with you.

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