[s-cars] A/C strength, 93 S4

[Ernest Seow]

The key to good AC is make sure you have sufficient high side pressure when 
you know the system is fully charged. If the low side is too low and the 
highside is too high with the correct charge, then replace the orifice tube 
if you haven't already done so. Its the cheapest part. They tend to clog as 
the car get older from normal debris wear from the compressors. Also 
replacing the accumulator will help also. An old accumulator that is 
saturated will tend to drop efficiency. Over time, moisture still gets into 
the system from the rubber hoses, thats why most AC shop replace them. Also 
make sure your system is running on recirc, and not fresh air, so check the 
flap to make sure it operating. When ambient temps rise above 80+ deg, the 
cooling temp will rise also. There is a chart to check this with Audi/VW 
vehicles. The design drawback of the UrS4/S6 AC is that the AC system is 
placed outside in the plenum, not inside under the dash like newer vehicles, 
so also makes the AC not as cool. I might attempt insulating my AC casings 
as its very hot and humid here in Florida.
Rgeards,
Ernest