1998 Chevy Malibu 3.1 with "belly leaking" A/C compressor

JackC

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Make
Chevy
Model
Malibu LS
Year
1998
Miles
101000
Engine
3.1
My Malibu compressor has the typical "belly leak" at the center of the compressor where a few drops of oil and some of the R134 have leaked out. The system still runs but not very cold. In other words, no catastrophic compressor failure, just a little leakage.

I want to replace the compressor and maybe the accumulator and orifice tube.

I finally found the unseen accumulator hiding between the rt. headlight and inner fender skirt, after undoing several shields, but I can"t find the location of the orifice tube.

My questions are :
1. Where specifically is the orifice tube on this car?
2. Do you think I need to replace the orifice tube and accumulator since this car only has 101K miles and no A/C problems ever since new ?
 

billr

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I would not replace either of those, but if you have a shop do the job they will probably insist on replacing the accumulator/filter.
 

grcauto

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I would just charge it with a can of 134A with oil and see how long it lasts. Might out last you.
 

JackC

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I would just charge it with a can of 134A with oil and see how long it lasts. Might out last you.
Thanks, that was my first idea but it only took about a year for the cooling to become poor after I noticed several small oil drops.

Some guy that has repaired hundreds of those belly leakers states that you do not need to add oil because there is a reservoir inside the compressor to keep the allocated amount inside. So, you could just add R134 every year or two and never need to add oil.

I would not replace either of those, but if you have a shop do the job they will probably insist on replacing the accumulator/filter.
Bill: I agree, that is my feeling also. I will do the replacement myself.

BTW, the a/c work we did on my Buick over 7 years ago is still working great. Thanks again for your assistance. Hard for me to believe it was 7 years ago.
 

grcauto

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Thanks, that was my first idea but it only took about a year for the cooling to become poor after I noticed several small oil drops.

Some guy that has repaired hundreds of those belly leakers states that you do not need to add oil because there is a reservoir inside the compressor to keep the allocated amount inside. So, you could just add R134 every year or two and never need to add oil.


Bill: I agree, that is my feeling also. I will do the replacement myself.

BTW, the a/c work we did on my Buick over 7 years ago is still working great. Thanks again for your assistance. Hard for me to believe it was 7 years ago.
Jack, if it's leaking oil it will need oil. NEW compressors come filled with oil. I think he was talking about replacing it.
 

billr

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It really comes down to how much oil you think has leaked out. If it is only a teaspoon or so, I feel it is insignificant. Put in the new compressor with the correct amount of oil for the compressor alone; which it will probably come wit already.

One of my pet peeves, over at a Saturn forum, is that it is often advised to drain the old compressor , drain the new one, and only put back into the new one what was in the old. The theory being that the rest of the "correct" amount of oil is distributed throughout the system. This totally ignores the possibility that any (all?) the oil has leaked out! So, if an old comp had no oil, the new one should go back in dry??? Not for me.

PS: One of my Saturns puts out 15F air on a 75F day. Yes, P has to manually cycle it on/off to keep the evaporator from icing up, but she sure likes that cold air!
 

JackC

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There has hardly been a measurable amount of oil released. Probably less than a teaspoon. The new compressor will be pre-oiled.

Today (90* F , 50% humidity) I put gauges on it. Clutch working.
Before starting engine 68-low, 0-high.
Engine started a/c on 28-low, 0-high.
5 min later @ 2000 rpm 25-low, 0-high.

Several hours later I rechecked and got entirely different numbers and the clutch did not engage.
before starting engine 40-low, 40-high
engine started a/c on 40-low, 40-high
5 min later @ 2000rpm 40-low, 40-high

I do not understand that enormous change.

Edit: The only ideas I have for the first readings being so unusual could be the engine had not been run for many weeks, or the high gauge was not connected correctly or the high gauge was stuck at 0 for awhile or ??
The second set of readings seem to make more sense and I think means the refrigerant is low, which it should be, since the compressor body has been leaking. I read that the 40 low and 40 high could be the clutch not on, and it is not on.
Am I just overthinking this? I know it needs a new compressor for sure. Maybe I should just do that and pray. I don't think any of these readings indicate a need to replace the orifice tube or accumulator.
 
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billr

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Alas, I do understand such weird gauge readings. I had the same kind of issues, a few years back. It turned out that the RED/BLU couplers had sliding-sleeve shut-off valves in them to minimize escape of any refrigerant from improper coupling or just from the hose volume dumping as they are disconnected . The sleeves in my couplers were not reliably opening, so I removed them. My couplers are Harbor Freight, but I suspect most (all?) couplers are similar in design.
 

JackC

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Bill: That makes sense because I could not get the High (red) coupler on my engine port and took gauges back to Parts store, where we tried it on a new a/c line. It was difficult to attach there also, but it finally attached. Tried it on my car and it finnaly attached after a tiny bit of lub in the gauge fitting. So we will disregard the first set of readings.

Ok, so today the readings are similar to yesterdays 40-Low, 40 High. They are actually 35 Low, 40 High. So, with my limited knowledge of a/c pressure readings, I think I do not have a orifice or accumulator problem and will simply replace the compressor.
 

billr

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I would first charge it up with refrigerant, I think it is so low the compressor doesn't even have a chance. Static pressure, with compressor not running, should be approximately the same as the ambient temperature in degrees F. Both high and low will be the same.
So, you should be seeing about 80 psi with compressor not running.
 

JackC

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I understand, but I have ordered a new compressor to install (without the orifice or accumulator) to eliminate the belly leaking one. I will let you know how it all turns out in about a week.
 

nickb2

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I would first charge it up with refrigerant, I think it is so low the compressor doesn't even have a chance. Static pressure, with compressor not running, should be approximately the same as the ambient temperature in degrees F. Both high and low will be the same.
So, you should be seeing about 80 psi with compressor not running.
Yes, agree, very typical. I am as usual late to game, but essentially, the norm is as bill said, I usually find comps dont work at around half charge.

But sometimes you cannot just rely on static psi, as hot temps will effect the readings.

this week, I did 2 volks golf condensers, both of them 2015-17 ish. both leaked at connections, weak point, and I am seeing this often, so for those who work on ac like me, and see volks jetta or golf, first look there.

but going back to jack original, belly leak, again agree with bill, no significant OIL leak.

From, my experience, if it is lets say 90ish farenheight, I would expect a full charge system to be around 10 psi higher than temp. if that makes sense.

I did find this on the net, but again, depending just on pressure, you might misdiagnose, cuz as temps drop, pressure does opposite, and vice versa. The practice of using gauge readings vs temp, vs humidity etc is NOT an exact science.

Plz see attached chart.
 

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nickb2

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with California and such areas going through a huge heat wave, relying on static psi reading is probably not a good idea, but if you are seeing lets say 40c outside, expect somewhere around 135psi on a fully charged system.

hope this help, even if i am late to game.

yes, I am canadian, so for you american boys and gals, 40c is around 104ish F.
 

JackC

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Thanks Nickb2

The gauge manifold set I borrowed has a schrader valve on one end of the yellow hose.

Does the schrader valve end attach to the refrigerant can or to the manifold ?
 
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billr

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Do you mean the hose has an actual Schrader valve, or does it have a depressor-pin to open a Schrader valve on what the hose will attach to?
 
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