u/Atla492

Hi, got a problem on a car few days ago. Its VW Passat B6 2.0 TDI 103kw from 2006. I got off the highway and felt the car making a rough noise at exactly 1800 rpm in every gear and it stops at 1850 and then everything goes back to normal. I'm worried about this and I'd like to solve the problem as cheaply as possible, so I'm asking if you've had any experience with this problem.