16v Diesel inlet valve inspection

The direct injection common rail diesels can suffer from inlet valve contamination with carbonised oil deposits that affect the air flow into the engine. This 'gunk' can also gum up the EGR system and the inlet manifold.

It is possible to inspect the intake side of the inlet valves without removing the head and if the inlet manifold is coked up, the EGR is coked up then it would be worth checking the valves to see what state they are in to help make a decision on the viability of the engine.



With the inlet manifold removed it is possible to use a cheap edoscope connected (one of these from Amazon) to a phone to get a reasonable view of what the inlet valves look like.

The camera is water and oil proof, has inbuilt LED lighting and is powered by the phone over USB. Getting some of the gunk on it just makes the image dim and removing the camera and wiping the dirt off restored the image. The endoscope app will also allow image capture images for later sharing



The valves in this engine had only a small amount of wet oily gunk on them and the inlet manifold had a small coating on it, with all those miles it was expected and replacing the PCV is expected to limit further problems after proving the EGR was working.


Tip: Remembering which photo was taken in which intake valve helps because there are 8 of them


Just 4 of the intake valves pictured using the USB endoscope probe to show the minimal oil contamination considering the 100K+miles it has travelled. The oil was soft and not baked on carbon.