Whats wrong with my Turbo?

Given the design of a turbocharger and the fact that the rotating assembly floats on a layer of oil, the actual failure rate of a turbocharger failing without outside influence is approx 2%.

The biggest cause of turbocharger failure is lack of oil, with most oil issues being down to the oil feed pipe. In most cases, the oil feed pipe is a flexible steel braided over rubber pipe. Over time, the oil feed pipe collects carbon build-up and can also crack and perish due to the heat cycles and general age. This in turn restricts the quantity of oil entering the unit, starving it of oil. We, at Turbo Rebuild, feel an oil feed pipe should be renewed every 25,000 miles to ensure good flow to your turbocharger and trouble free motoring and MUST be replaced when any work is carried out with your unit.

There are of course many other reasons for turbocharger issues, below is a handy chart to help self diagnose your issue:


Blown Turbo?

"I've blown my Turbo"  Many have been here, many havn't, so what is a "blown turbo".

The term blown Turbo basically means broken..... so you have broken the Turbo.  In reality, it is impossible to say you have broken your Turbocharger without inspecting.  The table above gives a great idea of what could be the cause of your Turbo problem, but below we go into a little more detail and give you an idea of what to look for on an external visual inspection of your Turbo.

Firstly you MUST NOT complete any inspection of the Turbocharger whilst the unit is hot, so please do not undertake this inspection when you have used the vehicle.  Also any inspection is completed at your own risk.  Ok, lets go....

So, the assumption of a blown Turbo will be one of a few symptoms which occur whilst driving, these are:

  • Sudden loss of power
  • Unusual noises from the Turbo
  • Smoke from the back of the car whilst driving

We are going to assume for the time being that the issue is indeed a blown Turbo, of course there can be many other causes of the above symptoms not related to the Turbo, so for this case, we assume they are have all been ruled out.

Part 1:

Firstly remove the Turbo air intake pipe.  Look inside the Turbo intake and you should see the Turbochargers impeller wheel known as the Compressor Wheel.  Check the wheel is uniform in shape with all blades looking the same and free of damage.  Check the wheel sits centrally in the housing and with only a small gap between the wheel and housing.  Ensuring the Turbo is not hot, pinch the shaft nut between a finger and thumb and push sideways to its maximum travel, does it rub against the housing, or is there still a tiny gap?  Now pull and push forward and backwards, can you feel any movement?  At best is should be the tiniest amount of play, ideally enough to feel, but not really see.

Next, remove the exhaust downpipe to reveal the Turbocharger turbine wheel, again look for damage to the wheel, and check the radial (side to side) play and axial (in and out) play.

Finally turn the shaft  with you finger and thumb and check the shaft and wheels turn freely and most importantly they turn together, if they don't, you have snapped the turbine shaft!

Part 1 of the basic inspection is complete.  If you have no wheel damage, and no excessive play, then so far, all is well.  Lets move to part 2.

Next, find the Turbo wastegate actuator.  This is usually a round canister with a rod attached that is connected to an arm on the Turbocharger.  On units with an electronically controlled wastegate actuator, or an electronic Turbo position sensor, it is important to connect your vehicles ECU and investigate any logged fault codes to rule out the Turbcharger wastegate actuator.  So if you have a mechanical Turbo wastegate actuator we now need to check its operation.  Holding the rod of the wastegate actuator, try to pull and push the rod.  In VNT Turbochargers you will need to pull the rod towards the actuator.  The spring loading of the wastegate actuator will give resistance, but the travel should be smooth and free of sticking or dragging.  On non VNT units, the wastegate actuator works by pulling out of canister rather than moving inwards, and the internal spring can be considerably stronger so can be difficult to move, but again should have no tight spots or restiction.


If you completed part 1 with out any concerns and part 2 has seen smooth movement in travel, then its quite possible you have not blown your Turbo and as such further investigation is required with the vehicle. 

If your initial inspection revealed an issue with your Turbocharger or you require a full detailed professional inspection, then Turbo Rebuild can offer full inspection and cost of repair quotations free of charge.