A/C makes noise after replacement

[Magister88]

Hi everyone

maybe someone can shed some light on the issue i have:

X5 2004 3.0i, The A/C system was not working when i got the car last Nov. The clutch was engaging but the hi/lo pressure sides would not change at all. i figured the AC compressor is most likely bad. its 15 year old car.. so this is what i have done:

1. new compressor from Nissens (says it's pre-filled but i checked anyway)
2. new condenser, expansion valve and desiccant insert.
3. flashed A/C lines and evaporator (with the solvent for AC)
4. new o-rings after putting it back together.
6. vacuumed for 1 hr.
7. the decal says 440g +-10. so i got 2 cans, put 1st can (348g) and 100g from the 2nd can. I used digital scale to make sure i do not overcharge the system.
8. followed the brake-in procedure: air vents open, 75% blower output at idle for min of 2 minutes.

The AC blows cold air but here are the issues:

1. the compressor started making knocking sounds when the HI side reached around 210 psi at which point the HI side dropped to 150 psi and the sound stopped. it seems stable around 175 HI and 35 LO

2. after the AC is on and runs for a bit and the AUX fun comes on, the compressor is making some whirling noises (not loud but still there, turning of the AC makes the sound stop.)

could this be low oil or something else, not sure how to proceed

Notes:
i could not find the total oil capacity expect that on the old compressor calsonic CSV717 had a label with 120 ml. and that BMW TIS says the compressor comes from factory with total fill of the system. and Nissens says the fill it to correct amount. i checked and drained the compressor it had around 100 ml came out so i added 20 ml just in case. (could 10 ml to much if 10 stayed inside.)