Exhaust Manifold Leak: Common Causes & Fixes

I had my Golf 2 TD (with SB engine) at the workshop, and now it's blowing exhaust out of a hole on the original exhaust manifold.
Specifically, this hole is located on the right-hand side when facing forward, underneath or next to the turbocharger.
Right next to it is another threaded bolt, and about 4 cm further along is the hole (approximately an 8mm or 10mm hole).

I'm now wondering if something important is missing, or what could possibly be missing.
Unfortunately, I have to stay at work and probably won't be able to get to the workshop until Monday, which is why I'm asking this question.


I think you'll immediately know what this is, right?



I found a picture and I've marked the hole I'm referring to in red.

"Normally, there's a threaded bolt in there, and the protective plate is screwed onto it."

Okay, so I did it right when I screwed in that screw.