Automotive Air Conditioning Information Forum

Recently the AC compressor and the condenser were removed from my 2002 Civic SI (hatchback). No oil drained out of the condenser. Does this mean that the quantity of oil in the AC system was low or very low? Or it is normal?

The quantity of oil that came out of the compressor was 1 ounce FL.

Thanks

"AC compressor and the condenser were removed"

Why??

Comp should have had more than that

The compressor was removed for replacement. It was almost 20 years old and I felt that it was time to get a new one. Despite having replaced the expansion valve and the evaporator last year, the AC system was not performing well.

The receiver/dryer was replaced as well.

I agree on the oil being oil being low. What I am trying to establish, based on the information provided in my original post, is how low: extremely low, very low, somewhat low.

There were 3 ounces of oil in the new compressor that was installed, but the car AC system needs a total of five ounces.

Thanks

"The compressor was removed for replacement" ?
Not sure it matters how low, even a little low is not good. Suggest a professional look at this

"the AC system was not performing well."
What did the AC shop say the cause was

You are correct in that the specs for your vehicle call for 5 fluid ounces of oil, PAG-46 in this instance. Additionally, 18 ounces net weight of R-134a are required for a full charge.

That being said, it's difficult to judge whether the one ounce of oil you drained from the original compressor should be considered low. Since the system capacity is only 5 ounces in total--a very small amount--it's probable that the evaporator, R/D, hoses and lines, and even the condenser, which seemed to be "dry," contained at least some of the remaining 4 ounces. I'm going to guess (and that's all it can be at this point) that the system *did* have the correct amount of oil in it originally and wasn't low.

Charles5654 wrote: ↑Mon Jun 07, 2021 7:20 pm There were 3 ounces of oil in the new compressor that was installed, but the car AC system needs a total of five ounces.

A couple of questions: Did you or the shop add two additional ounces of oil by distributing it to the condenser, evaporator, and R/D? If not, then the new compressor would have been severely starved for oil. Is the compressor still working or did it seize up?

There are many other reasons why an A/C system can fail to perform as it should. You didn't mention whether the system was evacuated and for how long, whether the correct amount of refrigerant was installed, and what the pressures were at what ambient temperature. Another potential issue is the TXV. I've seen some brand-new aftermarket TXV's fail to operate properly and cause inadequate or intermittent cooling. Do you still have the original TXV in case you or the shop need to reinstall it?

tbirdtbird wrote: ↑Mon Jun 07, 2021 8:49 pm "The compressor was removed for replacement" ?
Not sure it matters how low, even a little low is not good. Suggest a professional look at this

"the AC system was not performing well."
What did the AC shop say the cause was

Thanks for your reply.

The shop said that the AC system did not perform well, because the compressor was old and the car was high mileage

Al9 wrote: ↑Tue Jun 08, 2021 5:22 am Condensers, evaporators, driers, accumulators and compressors can store as much as 1 oz worth of oil even when nothing can actually be drained out of them. PAG and Ester lubricants are polar, so they cling to anything metal/desiccant media.

Seen different field manuals where they list an oil return procedure to be followed whenever replacing a still operational comp. Basically 10-15 minutes of AC on, fresh air, max blower speed, idle. Then you can recover the refrigerant and then get the old comp off the car, and a lot more oil will apparently pour out of it.

Thanks for your reply.

The shop performed the procedure that you described, but probably the AC was on for less than 10 minutes.

JohnHere wrote: ↑Mon Jun 07, 2021 10:22 pm You are correct in that the specs for your vehicle call for 5 fluid ounces of oil, PAG-46 in this instance. Additionally, 18 ounces net weight of R-134a are required for a full charge.

That being said, it's difficult to judge whether the one ounce of oil you drained from the original compressor should be considered low. Since the system capacity is only 5 ounces in total--a very small amount--it's probable that the evaporator, R/D, hoses and lines, and even the condenser, which seemed to be "dry," contained at least some of the remaining 4 ounces. I'm going to guess (and that's all it can be at this point) that the system *did* have the correct amount of oil in it originally and wasn't low.

Charles5654 wrote: ↑Mon Jun 07, 2021 7:20 pm There were 3 ounces of oil in the new compressor that was installed, but the car AC system needs a total of five ounces.

A couple of questions: Did you or the shop add two additional ounces of oil by distributing it to the condenser, evaporator, and R/D? If not, then the new compressor would have been severely starved for oil. Is the compressor still working or did it seize up?

There are many other reasons why an A/C system can fail to perform as it should. You didn't mention whether the system was evacuated and for how long, whether the correct amount of refrigerant was installed, and what the pressures were at what ambient temperature. Another potential issue is the TXV. I've seen some brand-new aftermarket TXV's fail to operate properly and cause inadequate or intermittent cooling. Do you still have the original TXV in case you or the shop need to reinstall it?

I use a product called Pittstop to estimate the quantity of oil in the AC system. I have another car and when the compressor was replaced in this other car, the entire AC system was flushed (removing, hopefully, the vast majority of the oil). So we knew how much oil we put back in the AC system and Pittstop indicated that the quantity of oil was fine, which was what we expected. But this is the only information on the accuracy of Pittstop that I have.

On my Civic, before the compressor replacement, Pittstop was showing a very low quantity of oil in the system, which I thought it was possible, because refrigerant had been added to the AC system in a couple of occasions (because of leaks) without adding oil.
When the compressor was replaced, the new compressor came with 3 fluid ounces of oil and we did not add any other oil, because the shop estimated that there were other 2 fluid ounces distributed in the AC system. Pittstop, however, is now still showing a very low quantity of oil, just a tad more than what it was showing with the old compressor. The AC system was not flushed before installing the new compressor.

The quantity of refrigerant (should be 18 ounces net weight, as you stated) that was put in the system was not weighed, but was estimated by the shop, based on the pressures. Unfortunately I don’t have those pressures.

I don’t have the old TXV any more. The TXV and the evaporator were replaced by another shop last year. They claimed that they used a quality aftermarket TXV (OEM equivalent).

To summarize the current AC system situation is the following:
• As stated, Pittstop reads very low quantity of oil
• AC works reasonably with outside temperatures in the low eighties, but poorly with temperatures around 90°F. The temperature of the air coming out of the vents is 68°F, measured with a food thermometer
• There is a noise coming from the AC system. It is not a grinding noise. It is more like a howling noise, not loud.

I am, of course, concerned with what is going on.

A couple of questions on the side, if you don’t mind:

Is it possible to flush the AC system effectively (excluding metal debris, of course) by removing the compressor and connecting to the lines where the compressor was, without removing other individual components?

What would be a good AC gauges/vacuum pump kit for me to buy for personal use (CPS, Yellow Jacket) ?

Thanks

I think you need to mention Pittstop at least once more so we know you used Pitsstop!