What is the best way to diagnose if the compressor has simply failed versus self destructed with metal fragment release? I'd like to determine that myself before purchasing parts to make sure I buy exactly what I need before getting started. Also, I assume gas removal has to take place first. Will it be obvious to whoever I take it to for gas removal?

fyi: 2002 Toyota Camry v6

AC Compressor is off

In my opinion, the contents of the compressor looked clean, but I can't say immaculate. I replaced the compressor, dryer and vac'd it for 30 minutes, then charged. I have cold air now... but for how long. We shall see.

Update: It has been about a year and the system is still going.

  • What is the make/model/year of the car you're looking at? While the basic function of an A/C compressor is pretty much the same, there's lots of variations. Dec 8, 2017 at 19:49
  • 2002 Toyota Camry v6 (also added to question text). Dec 8, 2017 at 20:26
  • if you want any kind of warranty they make you buy a new accumulator and flush the system. is it the clutch that failed?
    – Ben
    Dec 8, 2017 at 21:51
  • No. Clutch is ok. Dec 11, 2017 at 22:32

3 Answers 3


The first thing to check is if the compressor turns by hand and if it does how smooth it turns.

The only way to tell if the there is metal leaving the compressor is to remove the hose fittings for the compressor output line and visually inspect the inside of the fittings. A word of caution is that metal may have moved through the system and not be visible in any one connection. I pull apart as many as I can and get a good look with a strong light.

Even small metal particles can lodge in the expansion valve and cause the system to not function.

  • Thanks for your answer. I updated my question with pic. Take a look. Mar 21, 2018 at 0:49

In addition to Fred's answer I just want to add that the system must be fully evacuated before attempting to disassemble any A/C connection! Also, take a q-tip and swab the inside of these fittings. The q-tip should not have any grey color to it after swabbing. Sometimes compressor failure isn't catastrophic enough to send large metal chunks into the system but rather fine metal shavings. If your a/c system has any UV dye in it you will notice the oil in the system has a bright green color. This isn't anything to worry about.

  • Thanks for your answer. I updated my question with pic. Take a look. Mar 21, 2018 at 0:49

AC compressors fail, in the strict sense of the verb, whenever a mechanical part inside them breaks. So, a failure of the compressor, per se, necessarily implies a contamination of the AC system with different types of debris, which then requires a flush to remove not only the pieces of the mechanical parts that failed, which may greatly vary in dimension, but any contaminated oil (especially any oil charge that degraded, thereby losing its lubricating properties, leading to the compressor's seizure; one possible, and frequent, case may be running a compressor on a very low refrigerant charge, which implies higher than normal refrigerant vapour superheat and lower oil circulation, which both lead to an important overheating of the compressor and, therefore, a thermal degradation of the lubricant oil inside the compressor; another one may be hygroscopic lubricant oil which caught too much moisture, not successfully removed by the vacuum and by a saturated receiver dryer dessicant).

Diagnosing the failure of a compressor and its extent of damage, apart from removing the system's parts (most importantly, lines, liquid receiver/accumulator and expansion valve or orifice tube) after safely and legally evacuating its refrigerant, checking the color and purity of the oil drained from the system (through a recharge station; a certain quantity of oil, which of course has to be injected back in the system as new oil of the correct type and viscosity, is always drained by the machine along with the refrigerant, and stored in a separate container) or trying to turn its clutch hub (there has to be some resistance to movement but not enough to completely impede rotation without forcing the hub in any way. The following check, in order to avoid any injury risk, has to be done with the AC system off and the engine off and not being able to start; the compressor's clutch hub has to rotate smooth by hand, up to the point that all that it's needed to rotate it is one little finger; otherwise, the compressor has to be scrapped and it's not worth spending any more time on it) and feeling for any binding, is not necessarily a simple task: what may often fail on an otherwise healthy compressor "shell" may a compressor cycle related part, such as the control valve of a variable displacement compressor (a failure which may leave the compressor in a permanently stroked or destroked condition, and the former is the damaging one since liquid refrigerant, not before turning the evaporator into a giant block of ice impeding any airflow from the vents that is, may eventually find its way in the compressor slug it and pretty make it "Let it Go" by also covering it and the suction line with frost, while the latter leaves you with a compressor that can actually pump something, but not enough to satisfy the evaporator's thermal load), or the clutch coil of a clutch equipped compressor (especially if it features a thermal fuse in series with the coil), or even the thermal protection switch of a rotary vane or scroll compressor or the clutch assembly (if the hub plate gap increases making the compressor clutch cycle too much or not engage at all). Clutchless compressors are known to fail in a peculiar way: whenever the compressor starts seizing up, a connection between the pulley and the compressor's shaft severs, making the pulley freewheel. And, of course, what applies with clutch equipped compressors doesn't apply with them; the compressor's belt or serpentine belt has to come off to check how it failed.

As you can see, an ac system's failure does not necessarily imply physical damage to the compressor itself, but diagnosing the issue can be an hard task, which necessarily has to begin by identifying the model and type of the compressor, and is best left to professionals.

  • 1
    I'm not sure I agree with your statement "necessarily implies a contamination of the AC system". Is the clutch bearing the only bearing involved? Or are there other bearings in the compressor that are also open to the system? BTW, I updated my post with pic and progress. Mar 21, 2018 at 0:55
  • There are axial thrust bearings inside the compressors. With my statement, i meant that, whenever something mechanical fails inside a compressor (except for its control valve, which, rather than belong to the compressor's mechanicals, is only a part of it), a chain reaction develops that necessarily makes the debris end up inside the lines and, then, helped by the sudden equalization determined by the cutoff of the pumping action (also because car AC systems don't feature LLSVs, that is, essentially anti-equalizing solenoid valves), spread across the system.
    – Al_
    Mar 21, 2018 at 11:49
  • 1
    When the clutch engaged, the engine would bog down under the load of the compressor and kick off after a very short time. I knew this was bad so I removed the clutch relay until I could deal with it. So it didn't totally seize up, but there was definitely something wrong. Here's a vid of what was happening: youtu.be/HB8IPNJ-xmM Mar 21, 2018 at 13:41
  • 1
    No service and I've owned for over 5 years. I sort of guess that I had been running low on gas. Over 2017, it had freezed up the evap several times, but I had neglected to address it. Then the bogging down of the engine started. Mar 21, 2018 at 16:20
  • 2
    By letting the system run on a low refrigerant charge (and evaporator frost is caused by low refrigerant), due to lack of use or a unrepaired leak, you reduced your compressor's OCR (oil circulation rate, that is, the amount of PAG 46 oil that flows around the system in solution with the refrigerant) too much, up to the point that your compressor's organs wore and began binding up. That's why you should let your clutch equipped AC compressor run for some minutes each week and have the system properly checked and serviced by a trained professional periodically (every 3-4 years).
    – Al_
    Mar 21, 2018 at 16:35

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