Need advice. Rheem scroll.

[BTR]

System
Central A/C; residential home; Rheem scroll; matched system; has worked well for many years.

Maintenance
Low-restriction high-flow filters changed frequently; condenser coil & fan blades cleaned annually; evaporator coil clean (both sides - inflow and outflow); blower fan blades clean; condensate drain cleaned annually.

Problem
Approximately every 4-years, it freezes up (ice visible outdoors). Tech comes out, adds 1-pound R-22, then system performs within spec.

QUESTION
I'd like to "catch" the low-charge condition BEFORE it freezes up. Right now, the compressor is beginning to --- every so slightly --- resonate. It makes a oscillating rrrrr-RRRRR-rrrrr-RRRRR-rrrrr sound. I know that many things can cause the compressor to resonate. However, I would like to know if a "lower than optimal" charge can cause the resonance.

Please advise. Thanks for your help.

[pecmsg]

Fix the leak!

[bobboan]

Agreed, the leak should be located and repaired or new equipment considered if repairing is too expensive.

[BTR]

OP here. Yes, of course, fix the leak. Given that, I'm still interested to know if the resonation of the compressor indicates that the system is low on refrigerant. I'm aware that many things can cause a compressor to resonate. But, my question remains: Can low charge cause it to resonate? Please advise. Thanks.

[pecmsg]

Yes
No
Maybe

[BNME8EZ]

If I understand every 4 years the system freezes and a pound is added. Have the system serviced every 2 years and the tech will catch it before it freezes assuming you call early enough.