Dangerous Heatwave & A/C Died

I posted about 2 weeks ago that my climate control was making odd noises. But it was still blowing ice cold and working fine.

Based on the lack of responses to that post, I wrote the noises off thinking I might be making a mountain out of a molehill.

But the noises got worse & worse over the course of the next 5 or 6 days, until the a/c started blowing hot air on the 27th of June.

To say that it has been a TERRIBLE week would be an understatement. I've gone though the worst heat wave in 20 years while living in my car with no a/c. Had to check into a motel for a few days as my health was suffering.

I've been to 3 mechanics thus far...

The first shop did a diagnostic and found nothing wrong. Pressures were good, etc. This was probably because the a/c was still blowing cold at that time, and it was also in a shop out of the harsh sunlight, so the load/strain was much less (no noises).

The a/c died the next day.

I then bought a used compressor and had a second mechanic install it for me, along with putting in new freon. He initially told me that the compressor wasn't working, but when I picked the car up the next morning he said that everything was fixed! It was blowing freezing air while in the shop. This mechanic also said that my "low switch" was disconnected and that "might have" been the problem. About 20 minutes after leaving the mechanic the a/c started blowing warm again...like heater level warmth.

Took it to a third mechanic who said that - based on everything I explained - it could be the expansion valve. He replaced the fuel filter (strainer & cotton pad) and upon inspecting them, we could see tiny metallic particles on them. This is when we started to think that the system grenaded. Which might explain the very loud noises I heard before the a/c went hot.

He checked the pressures on each line and they were way out of whack and acting unusual. So he tried vacuuming/flushing the lines out to remove any debris in case there was a clog or to remove any of the metallic particles. This did nothing.

Today, he replaced the used compressor with a brand new one. He also vacuumed/flushed the lines again for a longer duration this time, to hopefully get any residual debris out of the system, along with removing the old freon and adding a new batch.

His thinking was: Let's try a new compressor first. If it works, great. If not, odds are high that it's the expansion valve.

After completing all of this, the pressures were both stable and normal this time. We started the car, and, once again, the a/c was blowing ice cold. However, within 15 minutes of leaving his shop it was blowing warm, just as it did before.

This debacle has cost me almost $1,000 and I'm still stuck at square one.

If it's the expansion valve, there's no way I'm getting that done. It's a tremendous job that requires 6-7+ hours of labor, in addition to the parts.

Is there anything else that this might be aside from an expansion valve?

The likelihood of THREE compressors being the culprit are astronomical (my original, the used one I bought, and the new one installed today).

Not sure if there's anything else that I can check, or if I should just sell the car as-is because I'll be moving into my camper soon.

I'd very much like to have the comfort of a/c over the next 5-6 weeks before the Prius is sold, as this heat is dangerous due to my health issues. And selling the car sans a/c will cost me a lot of money because I'd have to reduce its price by a lot.

Thoughts, please.

 

To address the responses thus far...

*All mechanics measured the amount of freon by weight. This I can confirm 100%.

*After both compressors were installed (used & new), all of the loud moaning, vibrating, and droning noises have disappeared.

*The a/c was working well, and blowing ice cold at all mechanic shops prior to leaving, and remained so for roughly 20-45 minutes after leaving. Then the air would turn warm again. This seems to happen once the car becomes stationary, but there might be no correlation there.

*No warning lights or codes are being thrown. This makes the inverter cooling pump idea that someone mentioned less likely IMO. But I'll check that out tomorrow. I replaced my inverter cooling pump 2 or 3 years ago, and I did get a warning light & code at that time.

*The filter basket and cotton filter tied to the original compressor were both taken out and inspected. The cotton filter thing (that looks like a tampon) was literally black on one end. From what I was told, it is not supposed to look like that. The tiny filter cup/basket appeared to have itty bitty metal filings/flakes on the screen, as did the cotton piece. This is what led the mechanic to think that the compressor grenaded and compromised the entire system. That might explain the harsh, worsening noises before the a/c failed.

*After removing the used compressor today (so we could install the new one), the mechanic emptied the oil to see what it looked like. It was a gray metallic color, like mercury. He said the oil should be a dark honey color. He pointed to this as strong proof that the system was corrupted by metal due to the grenaded compressor.

*The mechanic vacuumed/flushed the lines 2 times in order to clear any debris/filings from the system, in case his grenaded compressor theory is the cause. The hope was that once the lines were cleared (even mostly so) with a new compressor added, that the a/c would work correctly.

Things we'll be checking tomorrow...

Inverter cooling pump (just to be sure)

Cooling fans

Clogged condenser exterior. The outside of the condenser might have debris, which can easily be cleaned. Conversely, if the inside of the condenser was corrupted by a grenaded compressor, this would be very difficult to clean and would likely need to be replaced.

If any of the above 3 things aren't the culprit, the likelihood of it being the expansion valve is very, very high. At that point, I'll simply sell the car sans a/c and take a hit on the price.

I don't have the time or money to keep investing in this issue. So hopefully we'll catch a break tomorrow and find the cause.

 

Think I gleaned a few BIG clues earlier as to what's happening and perhaps the cause.

As many of you know from my post history, my Prius runs in ready mode for most of the day & night.

But I had to use a public restroom this morning, and I shut the car for about 30 minutes.

When I returned and started it, the a/c was once again blowing ice cold. And just like previous times, it petered out and went warm about 15 minutes later.

This makes sense. When the car is being repaired in the mechanic shops it is off most of the time, which allows the car to remain cool. When they start it, the a/c blows frigid initially, and then goes warm after I leave.

This points - IMO - to the expansion valve sticking, an issue tied to the cooling fans, or perhaps a faulty pressure sensor.

If it's the former, I'll leave it alone as it's a huge, complicated job to fix. But I'll take a look at the fans and pressure sensor later, as well as the fan motor, connections, etc. I might just get lucky and have those be the culprit...which is a lot simpler to remedy.

P.S. - Another clue is that once the a/c starts blowing warm, the compressor comes on but shuts off after a second or two. This cycle continues about every 30 seconds. So something seems to be shutting down the compressor...possibly to protect itself.

 

Thanks, RJ. Do you mean the inverter coolant pump itself? I'm assuming so as a faulty one might lead to hot coolant.

Also, where is the heater blend door located?