1997 e39 aircon not as cold as it used to be

it's just the gas, there's nothing you could really do to check it... it's cheap to refill, i got my E34 done with SP34E for $80AU (about $55US) and he came out to my office and did it

now it's so cold the little temp stick that he put in the vent went down to 0C ! now that's cold!

if you use your aircon often you will probably need to regass every 2 years

Usually, you can have someone turn on the a/c while you watch the little window in the fitting next to the dryer (a round pint-sized canister). If too many bubbles appear, or if it takes a while for the fluid to run by, you're low.

That is bullocks. My '91 E34 (with R12) has the original charge. If you have had to have it refilled every two years, you should get the seals or whatever is leaking replaced.

FloydR

My 95 e34 has the original charge as well. It did stop cooling sufficiently, though. It was a filter. If you haven't cleaned the filter under (behind) your dash every 25-30k miles, debris will build up and limit airflow through the dash vents

SNIP most

Quite the contrary. Lack of use is the culprit. The seals dry out, develop leaks and then the refrigerant leaves when pressurized. Good practice, cycle the A/C on every week or so even in winter .. just a few seconds to pressurize the system and circulate the refrigerant.

R / John