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Can too much oil cause high low side pressures?

Metal Man on Mon May 14, 2012 8:01 PM User is offline

Year: 2002
Make: Ford
Model: Windstar
Engine Size: 3.8
Refrigerant Type: 134a
Ambient Temp: 80F
Pressure Low: 90
Pressure High: 150
Country of Origin: United States

I had a 02 windstar(duel air) come in the shop today Static pressure was 20psi. So i recovered what little 134a was in the system. Next i vacuumed the system down for 30min then installed the proper amount of 134a( 3lb 8oz) Fired up the ac and noticed the low side pressures were way high at 90 psi while the high side was at 150 steady. Also noticed the compressor was making a noise. Next i recovered the 3lb 8oz of 134a i just put in back out. when i was done recovering the refrigerant i noticed the oil drain bottle on my machine had pulled out 4oz of oil. Thats the first time i have seen that much oil come out with the refrigerant. It's usually 1/2 oz or less oil. Sometimes nothing.

I'm wondering if this system has been over charged with oil in the past. Can too much oil cause higher then normal low side pressures?

JJM on Mon May 14, 2012 11:29 PM User is offline

Too much oil typically shows itself in both much higher low and high side pressures, especially the high side. Those 90/150 pressure readings seem to point to a compressor on its way out, either that or a missing or improperly seated orifice.

Do you have an analyzer to check the refrigerant you recovered into your tank? I would hate to see you contaminate your tank with who knows what, or worse some kind of sealer, slime or goo that might have been added.


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Metal Man on Tue May 15, 2012 7:37 AM User is offline

Don't have an analyzer yet but will soon.I know the importance of it.

I did notice the oil had a strong oder to it(smelled like alcohol). Smelled like someone had previous attempted to flush the system and did not get it all out. The owner says he had a new orifice tube installed along with a new compressor and accumulator. All by a shade tree.(actually this is the second compressor. The first one only lasted 2 weeks) The accumulator is ruined as well. He eventually fessed up to installing the new accumulator a day before putting the system back together. And they never pulled a vacuum at all. Just started throwing 134a out of a can to it.Along with an entire can of oil.

I told him basically we would just have to start back over from scratch.The oil was contaminated and probably over charged. We needed to drain and clean what we can and replace what we cant.

He may have already ruined the second compressor as well.

On a side note the orifice seams to be in the liquid line. Do you have to change the entire line or can the orifice be gotten to?

Edited: Tue May 15, 2012 at 7:41 AM by Metal Man

mk378 on Tue May 15, 2012 10:32 AM User is offline

Debris of three compressors, the condenser is bound to be clogged up. It's basically a total replacement at this point. Also there's clearly a leak somewhere, so check the evaporators closely. You may want to replace them too due to contamination issues.

Edited: Tue May 15, 2012 at 10:33 AM by mk378

Metal Man on Tue May 15, 2012 8:12 PM User is offline

Originally posted by: mk378
It's basically a total replacement at this point q]

Yeah thats pretty much what i explained to the customer.

He called today and told me he could not spend any more money on it so i guess thats that.There just gonna sell the vehicle.

Bad thing is he told me today that when the problem first occurred a local shop told him they would fix it for $500. He thought that was way to high and set about trying to fix it cheaper. In the end he spent more then $500 messing with it and now its in worse shape then when he started.

He paid well for that lesson!!

Edited: Tue May 15, 2012 at 8:15 PM by Metal Man

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