Well I took everything apart and it was quite a surprise...
First I removed the pipe from intercooler to intake manifold. It was quite oily inside. Is that normal or a sign of problems on the way?
Then I removed EGR, it looked exactly like the last time I took it off about 2 weeks ago.
After that it was time to take the intake butterfly off... and under the butterfly there was loads of soot/oil mix. In the part of manifold where EGR connects on it the airways were completely clogged.
I removed all soot in that area, but there is quite a lot of stuff inside the manifold, where air is sucked into cylinders.
I didnt try to remove the soot out of there, because I was afraid of some big pieces of gunk stucking in the pathways. There is a cover on the backside of the manifold, that should give access the complete manifold. Is it safe to remove that cover, or is that too much of a hassle?
I also noticed that my engine does not seem to have the swirl valves... is that posible?
I found the article that explains swirl valves on Opel/Vauxhal 1.9 CDTi (which should be same as my JTD 16V) but there is no sign of swirl valves on mine...
Judging by the pictures on the page 3 of the article
the swirl valves should be visible when engine cover is removed... but not on mine.
Now I will take the car for a spin... to see if anything has changed...