2011 v6 camaro air conditioning issue/tip

[drhillier]

Hello everyone, this is my first post. I am a professional mechanic, and I was given a 11 v6 camaro with an AC issue to diagnose. I first checked the charge, it was a bit low but had plenty to make it at least run. I looked at the data with a scan tool, something not all of you would have access to, but the hvac module showed that the compressor was commanded to run, and the clutch was engaged. My manifold gauge showed both high side and low side were at 115 psi, the outside temp was about 95 degrees. So I diagnosed it as a compressor failure, installed a new compressor, and everything worked as it should. I returned the car to the customer and off he went. Well, he returned to the shop with the same issue. The compressor was running, the charge was full, but it felt hotter in the car than it was outside. I installed a brand new AC DELCO compressor, filled it with oil, I was confident that the compressor couldn't possibly be the issue. I got more info from the customer, found out that he had hit a deer, and ever since then he had been having this issue. I searched all the information that I have access to, found nothing helpful. I searched this forum and still really found nothing that described the problem I was having. High and low sides were running equal at 115psi. Metering valve possibly? Anyhow, to make a long story short, I grabbed the inside of the compressor pulley and it spun with zero resistance. The brand new compressor snapped the shaft. I ended up replacing it again, along with the condenser, and metering block, flushed all the lines, put a new dryer bag in the condenser. After charging it up again and putting it through its paces, it passed with flying colors, had 35 degrees coming out of the vents, and worked great. I don't know why the compressor broke, I suspect it was just a faulty part. But anyhow, I looked here for info, so I thought it only fair to contribute. I couldn't find the same thread I was reading so I just put this here. The search doesn't seem to be working on my phone. I click on the search, and then when I try to type something in my keyboard flashes up for a second, then disappears. Hope this helps someone with a similar issue, I know it's hard to diagnose something yourself when you don't have a shop and expensive diagnostic equipment, but even after you replace a part, if you have a similar issue, don't rule out new parts!!

[G8One2]

Usually, in my experience. When a compressor goes bad, it grenades internally and sends metal throughout the system. If there is indeed metal in the system, flushing just the lines and replacing the dryer wont do you much good. You'd have to flush the condenser and evaporator as well. Most of the time its easier to replace these items, because its nearly impossible to get all the metal out of them. Any metal that had not been flushed out, is only going to kill every compressor you put on it. Possibly adding even more debris to the system when the new compressor grenades too. The expansion valves can also get clogged with debris when this happens.

The amount of oil is really important as well. Im sure you know this. Too much will cause excessive pressures and create more heat, having a negative effect on cooling performance, and can also cause the compressor to fail. Though usually they just vent themselves from the pressure relief on the back of the compressor. Too little, and the compressor fails due to insufficient lubrication. Usually they fail by seizing up or exploding parts internally.

I'm not saying this is your issue, because I'm not there looking at it with you. But A/C systems arent overly complicated. I worked on development vehicles when Ford was implementing r123yf. We were replacing parts, pulling dashboards, weight oil, blowing up compressors, measuring debris, weighing components before and after flushing and doing just about everything you could think of to the AC system of these vehicles. Needless to say, I've done a ton of this stuff in the not too distant past. You tend to learn how and why some of this stuff works.

[G8One2]

One other thing I would like to note. New compressors usually come with all the oil the whole system needs, pre-filled in the compressor. I know this for sure on OEM units, cant say for sure on aftermarket. Typically, you should drain the oil out of the old compressor, drain the new compressor and only add the amount of oil that came out of the old compressor, and any oil that came out of flushed parts (unless every component is brand new and has no oil, then the compressor has all the oil needed). Installing a compressor without doing this, likely is adding way more oil to the system than specified, and if your adding more on top of that, you just might have too much oil in the system. Again, not saying this is your issue, just speculation.