[Grogetter]

ain:
The 1990 camaro with 3.1 that I've been working on for a while needed a new compressor (old one leaked at the clutch seal and sounded like a rock crusher)
I went to O'reilley and got a reman compressor, receiver, orifice, PAG oil, flush and refrigerant.
I removed the compressor, orifice and receiver and flushed the system components, evap, cond and all lines with the flush and then blew them out with compressed air until no liquid was coming out. BTW the old orifice had some metal and garbage in the strainer.
Then, per the instructions, I added a few oz of oil to the compressor, turned it by hand and let it sit with the clutch down for a few minutes.Then I poured the remainder of the oil into the suction hose, vacuumed the system for 1.5 hours, then recharged the system.
Again, sounds of a rock crusher and no cooling. I kept adding R134 until the clutch stopped cycling at idle. I had a fan blowing on the condenser. Still, no cooling. After a while I gave up and wrote it up to a bad remanufactured unit.

I got a second compressor, receiver and orifice and all the trimmings. Went through the same process of cleaning, but this time I added all of the oil that would go in the compressor then added the rest to the receiver. BTW, I rotated the compressor by hand to pump all of the excess oil out of the compressor both times. Evacuated the system, charged it and got the same result.
Then, I opened the system and got all of the oil out of the condenser that I could, thinking that the high side was flooded with oil that couldn't get through the orifice. Then I recharged the system and tried again.
Once I got the system closed, compressor running, small fan on the condenser I was seeing the about 30 psi on the suction side and 200 to 250 on the high side. The compressor sounds like hell when it's been off for a while then comes back on. Then quiets down a little bit as it runs but still noisier than it should be and no cooling to boot.
Can anyone give me some advice before I start throwing things??
Please!!!

Thanks

 

[LATECH]

How much oil are we talking? Sounds like way too much oil to start with.
Also...is the condenser a serpentine or a tube type?

 

[boothboy]

How much refrigerant did you add? The proper amount should be on a sticker probably on the evap case. With refrigerant more is not better.

 

[Grogetter]

I've added 8 oz of PAG oil each time based on adding up what the service manual says to add for individual component replacement. That total is 9.5 oz. However, further reading indicated that the total system capacity is 6 oz if the system is completely flushed. Bear in mind that the service manual was written with R12 in mind but I would think the oil amount would be the same. It also calls for 3.5 lbs of R-12. I wouldn't think it would take that much R-134 but that's just a WAG.

As for how much refrigerant I added, I don't know as I was feeding in vapor from a large tank and don't have a scale to use.

The condenser is two parallel passes. One manifold for all of the vapor in and another manifold for all of the liquid out, both on the same end of the condenser with u bends on the other end. The liquid outlet is at the bottom of the liquid manifold so it doesn't seem that any oil would be trapped in the condenser after flush and blow out.

I've serviced auto a/c systems for a long time as a shade tree mechanic. Used to be an appliance tech servicing window units and refrigerators so I'm not without training but I must say this is eating my lunch.

Thanks for any and all help.

Grogetter

 

[boothboy]

Well a overcharge of either refrigerant or oir can cause the condition you describe. Too much of either can cause compressor hammering.

 

[Grogetter]

OK. I'll stop by O'Reilley this afternoon, pick up some fresh oil, evac and flush the system again, start over with 6 oz of oil, all of it in the receiver (the compressor should be well lubricated) and try it again.
Any other words of advice would be welcomed.:drunk: