Hi All,
does anyone have an explanation for why Benz diesels tend to idle rough at stops when warm?

I'm sure many of you have noticed your oil pressure dropping at stops, it can freak out many new drivers who aren't used to it.

My 190D 2.2L has always idled poorly at stops when hot, and it has gotten worse to the point that I sometimes think it might stall. I've tightened up the throttle cable a little, which has helped.

Can anyone explain why diesels behave this way when hot?

Thanks!