Turn signal slowdown/lag

[Kuszotke]

Hello,

My game slows down when i turn on my turn signals. The slowdowns occur "to the rhythm" of the turn signal sounds. It seems like it's related to the blinker sound?

It only happens in first person view, in the cabin. Everything was fine until just now when i launched the game.
Headlights, beacons don't cause this. Only turn signals/hazards.
Google search hasn't helped much, people were just blaming their PCs or the game engine, but hell - i didn't have this issue literally 3 hours ago! It just appeared out of nowhere.
I encountered it in the past, long ago but i guess it just fixed itself somehow. Don't remember how.

Specs:
MSI GTX 970
i5-6500
8GB RAM
MSI B150 mobo

Thanks for the help

[Kuszotke]

Right - i figured it out.
The problem was caused by the "ETS2 [Tool] Construction Roof Grill + Led Bar" mod.
I switched to a truck that had the roof grill installed, that's why it popped out of nowhere.