6.9forever
Noble
An interesting experience that I would like to share:
My 6.9's air conditioning was refrigerating air so well that condensation was forming on the outside of the condensor box behind the dash. Once the condensation reached a certain thickness it dripped down and wet the carpet in the footwells. Initially I thought there was an inaccessible crack or bad seal in the system but this proved not to be the case. It is very difficult to find a leak that doesn't exist!
After seeking the help of an air conditioning guy introduced by Styria, the temperature at the dash vents was measured at 6DegC provided the blue dial was not turned past the mark shown in the photo below.
The mark signifies the point at which recirculation commences. If the blue dial was turned to max, the temperature at the dash vents was 3.5degC and after a time with humid atmosphere condensation and wet carpets would result.
The moral of this story is to keep the dial below the recirculation point or risk smelly carpets and a wet underlay that can lead to floor pan rust eventually.
I suggest you pull up the carpets in your w116 if it has air conditioning and check carefully for wet underlay. This stuff soaks water like a sponge! If the original underlay has degraded don't hesitate to get rid of it and replace with a suitable modern thermal and sound insulating underlay such as Dynamax.

My 6.9's air conditioning was refrigerating air so well that condensation was forming on the outside of the condensor box behind the dash. Once the condensation reached a certain thickness it dripped down and wet the carpet in the footwells. Initially I thought there was an inaccessible crack or bad seal in the system but this proved not to be the case. It is very difficult to find a leak that doesn't exist!
After seeking the help of an air conditioning guy introduced by Styria, the temperature at the dash vents was measured at 6DegC provided the blue dial was not turned past the mark shown in the photo below.
The mark signifies the point at which recirculation commences. If the blue dial was turned to max, the temperature at the dash vents was 3.5degC and after a time with humid atmosphere condensation and wet carpets would result.
The moral of this story is to keep the dial below the recirculation point or risk smelly carpets and a wet underlay that can lead to floor pan rust eventually.
I suggest you pull up the carpets in your w116 if it has air conditioning and check carefully for wet underlay. This stuff soaks water like a sponge! If the original underlay has degraded don't hesitate to get rid of it and replace with a suitable modern thermal and sound insulating underlay such as Dynamax.
