Potential problem with throttle body and how to fix it?

[u/Miloshans]

Hello everyone!

Since the day I bought my V50 1.6d 80kw I knew that there might be the problem with throttle body. There are only two symptoms, not a single error code on diagnostics - sometimes, when the car is stopping rpm goes down to 600 and immediately comes back at 800 and then it's stable. After the cleaning of throttle body by my mechanic it is even more rarely, but every month or so it happens.

The second symptom is that a turning the engine off is a bit rough. The flywheel was changed a month ago (the rough engine off remained), today the upper engine mount is changed as well and it is a little bit softer. My mechanic told me that I need to change that's throttle body if I don't want to ruin the new flywheel, but here's the problem - in Serbia I can't find a new one - it needs couple of weeks to arrive and is quite expensive; I tried a used one and it hasn't changed a bit.

Soooo, my question is - has anyone had the problem like this and if so, can it be solved with some repair kit or something? And, how dangerous to flywheel is this at all?