The EGR seems to be intact

What a bugger.... :yikes:

There are some bloody cowboys out there. Some of them are even on YouTube... this chap completely missed the crushed vaccum hose on the #1 cylinder intake... and then re-crushed it again when installing the manifold...!!!

https://youtu.be/tVbtiADXxdM

SMH... :rolleyes:

It would be very easy to drop something into one of the intakes when removing it - one of the intake mounting nuts perhaps?

I was SUPER careful when I removed my intake to change the glow plugs - I even used a magnetic probe to lift each nut/bolt/washer from it's location etc.

Sorry to your engine in this state... :(

The piece that came out doesn't really resemble anything that could just fall into the intake. The intake I have is without the swirl flaps, so at least there's that.
The shop replaced all valves in cyl 4 and assembled everything back together as I decided that at this point it's not financially reasonable to go deeper into the block.
After assembling everything there's still that tapping sound that's heard the best from underneath the car. Bearings I suppose. Here's a vid for you if interested:

That same tapping began before the engine started to run rough. So all of this could have easily happened due to a bad injector.

So basically I just paid 1000€ to find out something that could have been also found with an endoscope and I still ended up with a broken engine.

Current plan is to find a replacement 2nd hand EU3 160KW engine, which seem to be in the ballpark of 500 - 900€, depending on various factors..could be worse.

Update.

My X is currently on the lift and the block swap in underway. I did find a 2nd hand bare block for 500€ in relatively good condition. Didn't find any internal damage so far, but did decide to refurbish the cylinder head.
Injectors were sent off to a test stand.
Replacement block will get new chains + bearings.
Will be a hefty bill from this shop after all is done..

https://i.imgur.com/SC8PiB6.jpg