How to perform a boost leak check between turbo and throttle body on a 20VT. I am sure it will be almost identical on a 16VT.

For a downloadable PDF version of this guide please click this link.

Guide Courtesy of Joe - CountryCruising

Tools needed

Flat Head Screwdriver
Small tin or jar ~50 mm outer diameter (WD40 can may work depending on the volume you have)

Jubilee clip suitable for 60-70 mm outer diameter
Trolley Jack
Axle Stands

This guide described how to test the boost pipes between turbo outlet and throttle body.

Jack your Coupe up and secure on axle stands with the hand brake on. Suggestions for suitable positions for these can be found on the how to change the turbo how to guide.

If your Coupe still has one remove the Fiat OE clip attached to the U shaped pipe on the turbo cold side outlet

click to enlarge .

Remove the U shaped pipe and place the small jar in the part of the pipe which originally went over the turbo outlet and secure the jar with your new jubilee clip.

@@ If you decided to use a glass jar be sure to not overtighten there is a risk of glass smashing into your face at close range @@

Now you are ready to perform the test, get a friend to start your Coupe, it will pull a vacuum on all the boost pipes between throttle body and turbo outlet, testing all your intercooler pipework as well. It will then stall.

The soft pipes will deform in shape and slowly reinflate. If you have a leak in your boost pipes you will hear a whistle.

Here is a video of what happens including the whistle:

I found a split pipe round the back of the manifold that I wasn’t aware was split:
click to enlarge

You can then deal with any split pipes & remove your tin / jar, replace the outlet pipe onto the turbo with the new jubilee clip, remove the axle stands & lower your Coupe to the floor.