Hi there,

I would say yes that is what I saw on my car, the patches got larger and larger and were also visible on the turbo heat shield aswell.

Not sure about the smoke tho as my car didnt smoke much anyway...

Also not sure what disconnecting it would do or not do to diagnose your problem as I didnt look into it?

My guide to removing them is slightly different in your case as I don't have those 3 pipes infront of the valve, not sure if this will make it any more difficult to do.

Good luck! Neil.