sorry I had to ask,

1) How do you determine your system is running low? Base on noise? Coolness? or what?

Some say use the guage some say don't plug any guage unless you know something wrong with the system. By plugging in the guage you are taking the risk of introducing stuff in the system!

I really don't know and I really don't want to get a new compressort because I don't know the system is low on oil and let it ran as it is!

JackD, do you mean you never recharged the system, never touched the system in all that 15 years and 382K??

Car in concern is W140 1992 M104 engine. Dunno if its R12 or not.

Any light will help.