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Low side high and high side normal

vdiaz133 on Sat May 22, 2010 6:24 PM User is offline

Year: 2001
Make: Saturn
Model: L300
Engine Size: 3.0
Refrigerant Type: 134
Ambient Temp: 85
Pressure Low: 50
Pressure High: 200

I bought a 2001 Saturn that did not run with a locked up a/c compressor.

I replaced the compressor, accumulator, expansion valve and flushed out the evaporator and condensor.
I then evacuated the system for about an hour and then added 24oz of r-134 refrigerant (system requirement is 2.09lbs).
I turned on the a/c and ran it with the doors closed, windows down, and the fan at full speed. Guages showed low side 50ish, high side about 180-200 and compressor never cyled off.
Even thought the system wasn't completely full of regrigerant I didn't want to add any more becuase of the low side being at 50psi.

So then I decided to replace the expansion valve, with a new one, thinking it was defective.
After replacing the expansion valve, I evacuated the system for an hour and added 24 oz of refrigerant.
I ran the a/c again and the numbers were unchanged. Low side 50ish and high side about 200.

I'm to the point where I think it could be a bad compressor but don't really want to go thru the trouble of replacing it.
Any ideas?

Im really stuck on this one


mk378 on Sat May 22, 2010 10:35 PM User is offline

2.09 lbs = 33.44 oz. Would be best to have a full charge before trying to diagnose anything.

Edited: Sat May 22, 2010 at 10:36 PM by mk378

vdiaz133 on Sat May 22, 2010 10:40 PM User is offline

That's what I was thinking but I was afraid to fill it up completely since the low side is already at 50. I will top it off completely tomorrow and let you know what it does.


vdiaz133 on Sun May 23, 2010 10:32 AM User is offline

I went ahead and topped it off this morning (give or take an ounce or two) and still no change.
Low side 50ish
High side 180ish

Any ideas?

TRB on Sun May 23, 2010 10:47 AM User is offlineView users profile

What was the flushing process? You "could" have a little extra oil in the system.


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vdiaz133 on Tue May 25, 2010 11:38 AM User is offline

I removed the condenser and evaporator and flushed them with "Quest Clean and Flush" using the "Mastercool flush kit". I then blew them out with air until nothing came out of them. As far as the oil.......I added whatever the compressor recommended (I think it was around 8oz).
It might have a little extra oil but how much oil would be to much oil, 1oz, 5oz?
How would I remove a little oil to see if makes a difference?

bohica2xo on Tue May 25, 2010 2:24 PM User is offline

You have a variable displacement vane type compressor. They can sometimes be a PITA when recharging an evacuated system.

Is the replacement compressor a new unit, or a reman?

Sometimes it takes a little extra refrigerant to get the control valve to settle down.


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~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

iceman2555 on Tue May 25, 2010 8:01 PM User is offlineView users profile

The charge rate for this vehicle is very critical.....the system should be charged with the proper equipment.
Another issue is the flush chemical utilized. This is a ester based flush chemical. In many instances this chemical has proven to not clean the systems as one would expect and residuals are almost impossible to remove.
The first issue would be to insure that the system is totally charged.....then and only then can a realistic evaluation of the system be completed.
Good luck!

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