Renault Master 2.5L diesel turbo 2004 extremely poor running.
I was asked to drop in to one of my more local garages, for a bit of help with this vehicle. It was running very poorly, in fact it was clearly misfiring.
They really just wanted me to carry out a quick compression test, as I can do it quickly with the scope.
So that was what I did; well, a relative compression test anyway.
As you can see, in the image below, I also used a cylinder reference by connecting a dummy injector to No.1 cylinder and by using a low current clamp to capture the triggering.
As the image shows, cylinders 2 and 3 are low on compression. As soon as I saw that, I thought; Head gasket! because the low readings were on the two adjacent cylinders.
After the cylinder head was removed, the fault became clear.
This really shows the power of the scope.
Mark Stammers Diagnostics 