Questionhi, I'm a mechanic myself but just dont do a lot of a/c at the shop i work at. i've got an 84 cadillac rwd fleetwood with a 350 chevy (6 groove belt drive system) that i installed. the a/c system is original for the car, just using a compressor from a 90 chevy pickup. and when the a/c is turned on, after a short period of time it starts to give a louder vibration noise that resonates into the passenger area. you can feel the vibration on the low side hose especially. I changed the a/c compressor at the beginning of the season, changed the orifice tube, and have discharged and recharged the system twice since then to eliminate any chance of air in the system. I preoiled and spun the compressor when it was replaced. forget oil amount but used alldata specs for proper amount. no hoses are rubbing anywhere, belt drive is all new. when you're on the throttle the noise and vibration is gone, but when u let off the throttle and coast or stop at a light, thats when it vibrates. pressures are all good on the manifold gauges. kinda scratching my head on this one, missing something simple, but just can't pinpoint it. any ideas?
AnswerHi,
When the system is vibrating is there any indication on the gauges that the refrigerant flow is causing the vibration? IE is the low or high side needle fluctuation or bouncing or are they stable?
Thoughts...
- The 84 is R12 so what refrigerant are you using?
- It will be a CCOT system so have you tried using a variable orifice tube or are you using the standard R12 one.
- How much refrigerant and type are you putting into system?
- Is there adequate cooling on the condenser with this retrofit you have performed? What kind of cooling fan are you using and have to tried to hit the condenser with water to see if vibration in system changes?
Wayne
