Hi All,

I own a Mercedes 200E 1990 model with 350,000km.

Recently, my aircon keeps making intermittent noises - soft hissing and loud pant/sneeze while driving. I presumed these noises are made by my aircon because they disappear whenever I switch the aircon off. These two types of noises occur independently of each other.

When the loud pant/sneeze occurs (as if releasing a gush of air), the car would feel a slight jerk/strain and my oil pressure would dip slightly before rebounding. This jerk/strain and oil pressure dipping does not happen when the aircon hisses softly though.

What could possibly be the reasons for these different noises and what should I do to rectify them?

Thanks and best regards,
skyluck2001