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Whistling from expansion valve

obriend78 on Wed July 21, 2010 12:25 AM User is offline

Year: 2000
Make: honda
Model: civic
Engine Size: small
Refrigerant Type: R134
Ambient Temp: 100
Pressure Low: 70/40
Pressure High: 180/240

New compressor, condensor, dryer, expansion valve - removed and had AC Kits hecat flush evap and all the lines - added 7 oz oil 22oz freon.
Seems to be cooling ok once it gets going.

The 2 numbers above are the lo/hi at idle and at 2000 rpm??
Also I hear a prominate whistle from the expansion valve when ever the compressor is running?

If I evac the system again - how much oils should I add back in (I need to replace a stupid shrader valve)

ice-n-tropics on Wed July 21, 2010 4:30 PM User is offline

Envision a orifice with a shaped pin that controls refrigerant flow inside the expansion valve body. It is similar to the carb on my 2 cycle Suzuki.
These inner workings of a thermal expansion valve (TXV) are shown on page 35 of the book "How To Air Condition Your Hot Rod" that is avaliable from Amazon.

If the TXV has poor machining tolerances the metering control pin is not located in the center of the orifice. This causes the pin to either spin or to chatter and make objectional noises. Chrysler mini vans had a 30% warranty problem with their noisy EATON TXV poor machining for the rear auxilary evaporator. The fix was a Fuji Koki TXV - try that or the genuine Civic TXV.
Also the replacement scroll compressor from Sanden already is loaded with all the oil that you need. Your extra 7 oz that was added needs to be removed for intended cooling. The excessive oil charge may agrivate the noise problem.
Very little oil is removed during evac. R&R m/c have a oil recovery bottle which shows the amount of oil removed if the bottle was empty before evac.

Isentropic Efficiency=Ratio of Theoretical Compression Energy/Actual Energy. How To Air Condition Your Hot Rod

Edited: Wed July 21, 2010 at 4:46 PM by ice-n-tropics

Dougflas on Wed July 21, 2010 9:18 PM User is offline

You may not have to remove the charge to replace a schrader valve if you can locate the proper tool for ths. Try Master cool, robinair, Ritchie Yellow jacket, CPS as manufacturers. Check with Tim at ACkits

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