Automotive Air Conditioning Information Forum (Archives)

drhill on Thu November 15, 2012 4:23 PM

Year: 1998
Make: Jeep
Model: Grand Cherokee
Engine Size: 5.9
Refrigerant Type: 134a
Ambient Temp: 68
Pressure Low: 80-15
Pressure High: 80-125
Country of Origin: United States

I just did headgaskets on my 1998 jeep grand cherokee...ac worked perfectly before the teardown, now that it's back together I have a few issues. One - foamy ac oil coming from the high side port when I disconnect the high side line to my gauges(which is positioned very low on the side of the compressor) . The other is very short cycling - maybe 2-3 seconds engaged, followed by 20 to 30 seconds disengaged. the readings start at about even high and low side (approx 80 psi) and high side rises to no more than 125 and the low side plummets from 80 to 15 in 2-3 seconds before it cuts off. I tried adding some 134a to see if anything changed....the pressures on both sides rose with more refridgerant...so starting closer to 100 psi both sides, high side rising to 150 psi in 2-3 seconds, low side dropping to 25-30 psi in 2-3 seconds before cut off.

Any ideas? Clogged orifice?

Thanks for the help!!

GM Tech on Thu November 15, 2012 4:25 PM

Not surprised at 68 degf - there's not much to do....may not be a thing wrong...

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The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

drhill on Thu November 15, 2012 4:47 PM

I would normally agree - but it does the same thing in warmer weather...say 80 degrees

GM Tech on Thu November 15, 2012 4:54 PM

Probably loss of charge due to a leak- recover and weigh refrigerant to be sure...

-------------------------
The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

drhill on Thu November 15, 2012 6:18 PM

ok - makes sense, is the foamy oil something to worry about or no?