For those who service their own a/c systems, you may wonder which type of PAG oil to use. There are 3 weights : 46 / 100 / 150. It appears the original OEM spec was 150 but it is now 46. So, if you go down to the parts store buy PAG 46.

Now, how do you know if you need more oil???? Hmmm, don't know but I was going to add a couple of ounces to my 20 year old a/c system anyway. Seems like the smart thing to do.

 

Add pag oil if the r134a charge is low. The only way to verify charge level is to have the system evacuated with a proper recovery machine.Jaguar s of this vintage have used Denso compressors and they always use pag 46.. Pag 150 is for older style GM compressors. Pag 100 is for sanden compressors.
An overcharge of oil will cause issues with cooling and may damage the valve plate inside the compressor.
Evacuating the system does not remove oil except in very small quantities near the service port.
Do not add 134 with oil or sealant to the system. the magic a/c pro products sold in stores may cause more problems than they fix.
Be careful and do no harm