I've been experiencing loss of power and build up of soot in my EGR and intake manifold system. Typical diesel yada-yada...
Weekend before this weekend I cleaned my EGR valve. It was a complete mess, proper sootfest. The power restored for a couple of days, but I felt it started lagging again. So this weekend I followed kez's guide and cleaned out more stuff - the EGR pipe and valve, map sensor and TB. It was ugly.
Now below you'll see the EGR after one week ~300km. Could be that this soot came from the next-by egr pipe, because I had not cleaned it. But on the other picture you see the solenoid. I unmounted the metal part and noticed the surface between plastic and metal was also sooty. And the solenoid on the picture when pressed down would not pop up. Might be wrong, but isn't it supposed to do that if it works properly? Anyways, the valve on the metal part works well.
So the question really is how could I make sure if the EGR valve is still working or not working before I go buying a new one? I mean the soot buildup might be due to something other completly.
Is it possible to tell from the solenoid or by diagnostics?