Turbo check | How to test a turbo

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  • OVERALL DIFFICULTY INDEX: 3/10
  • IF YOU HAVE NO TOOLS YOU SPEND $ 10 TO GET THEM FOR THIS JOB
  • IF YOU HAVE NO EXPERIENCE YOU SPEND 1 HOUR TO CARRY OUT THIS JOB
  • RISK OF BURNS, SEE BELOW​

BEFORE YOU START
  • Be careful not to touch any hot part of the engine especially this task is to be carried out engine running with bare hands for the leak check.
  • Be careful not to touch the cooling fan if such risk is possible in your vehicle.
  • See our button links at the bottom of page for further turbo inspections and tests. 
DISCLAIMER:
Our pictorials are of informative nature and do illustrate works carried out by ourselves at our own premises for our own use and satisfaction.
Readers who envisage to carry out similar works inspired by the below method shall do this at their own risks and liability.

Very first turbo check: making sure it spins

You are suspecting a low turbo performance and would like to carry out some tests on it to eliminate some possible causes or further investigate the failure.

Start by removing the air hose and make sure:
  1. No loose object is there like a nut or screw. You should just find a bit of oil.
  2. It spins freely and silently for a few turns. Please use a screwdriver to turn the impeller as it will be very hot.
  3. It rotates smoothly without any hard point or "jerky" movements.
  4. No trace of the impeller touching the compressor's casing is there ​

Turbo lubrication visual inspection:

Take out the lube oil supply banjo bolt and make sure the bolt and its seat are free from any carbonized oil or solid material.
You should only see liquid oil of dark brown color on the inner wall of the lube hose connector (right).
Do not proceed with the banjo bolt removal however prior to making sure you have spare copper ring seals:

Turbo air leaks check, testing for leaking turbo hoses

With the engine running, put your hand around each air hose and feel if any air leak is there.
Include the inter-cooler and try to pass your hand as much as possible on the three visible sides.
You will never be able to check its front side with your hand.

Buy your turbo parts here:

Continue with more turbo diagnostics:

Click on any of the below links to visit more advanced turbo tests or return to the main page: