Oiling an AC compressor

[SWRT]

Ok, so on my wife's 98 Forester I decided to put new freon in.
The compressor sounds a little whiny, I guess would be the way
to say it. I've had the freon evacuated and currently it's sitting at
a vacuum. The system had a small leak before due to a bolt not
being fully tightened, I suppose because a little freon escaped from
there when putting the fitting on the low side...or something. It was
late last night. Either way, tightened the bolt up and the vacuum is
holding. My question is...should I add one of the small, pressurized
PAG 100 cans in there or take the compressor off, get rid of all the
oil and refill it. Currently I'm not sure how much oil is in the compressor.
Autozone said it takes PAG 100 and either the whole system's capacity
is 5.2 oz minimum or it's 5.2 in just the compressor. Anyone have any
advice for me? Should I use one of the small pressure cans of oil that
only contains about 1oz of oil, 1 oz of some form of cold stuff and 1 oz
of refrigerant or should I just take it off, dump and refill the oil and
put the system under vacuum again before adding the freon. I know very
little about AC systems and I'd appreciate any help. Thanks guys!

[Legacy777]

I'm not sure if you've tackled this yet....Most of the oil in an AC system is in the AC compressor. About 1 oz may be in the receiver drier, 1 oz in the misc lines, and the rest in the compressor.

My recommendation would be to just add 1 oz of PAG 100 via a pressurized can. The combination r134a & oil may not have PAG 100 oil, so if you go that route, you need to check.

I will say though that if the compressor is making noise and it's the internals of the compressor, it will eventually fail. There's not much you can do about it other than maybe add the 1 oz oil and use it until it dies. I would suspect the noise however is probably coming from the compressor clutch. You'd have to do some additional checks to verify that. Try spinning the clutch by hand to see if it makes any noise. If it does you may be able to remove the clutch. If it is the clutch, the noise won't hurt anything.....so unless it's too annoying I'd just leave it be.