Gen 3 A/C

Ours was at Toyota yesterday. They said it was "normal", no leaks detected, and they evacuated and recharged it. Was able to get it ice-box chilly after, so hopefully all good.

I know last fall the sight glass was showing a lot of bubbly froth as the fans (and compressor) ran. Took a look yesterday, post appointment, couldn't see squat. I kept watching, waiting for it to stop cycling, which usually will cause a swirl of bubbles, but maybe cus I'd set temp to LO, it kept running. So figuring to raise the temp I opened the door and noticed it was really chilly in there, so just packed it in, lol.

 

As I think about it, it would have probably been cheaper to get my own gauges. But then I wouldn't have known just how low it was and wouldn't have had dye to put in it. And I would have had to get a sniffer to look for leaks. I had a 15% off coupon and they rounded that discount up from $36 to an even $40, which got me out the door for $243.49. That's been my only repair so far in 17 months and 23.000 miles of ownership. It just turned over 75,000.

A/C should get a nice workout today. I'm heading down to MacDill Air Force Base in South Tampa for the big air show. Only admission is lots of patience as you wait to get in.

 

Still running on cryogenically cooled outside air here. Noticed when I got in the car yesterday the fan (solar panel powered) was blowing nice cool air into the car, as if the A/C system was cooling it (car was off). Today we are predicted to have actual warm ambient air (24-26C). I might even be tempted to allow the car to turn on the A/C cool function.

 

Well, the A/C didn't get as much of a workout as I expected. Cloudy skies and about 80°. Gave up getting into MacDill. Took an hour to get within 3 miles, as expected. Took two more hours to cover the next mile with two more miles yet to go. Google Maps showed no relief in sight, so I turned around and came home. A/C did fine, though, and I showed 72.8 mpg on a round trip of about 74 miles.

 

Yeah it's punishing to your Fuelly score, crawling in a traffic jam. Very frustrating too.

 

Update. We've had some upper 80 to 90 degree weather, although it's been raining the past 2 days and will all week. During the hot afternoons that A/C was positively loafing. Makes me wonder if maybe it's been slowly leaking since before I even got it. I don't remember it ever cooling that quickly before. And that was in ECO mode.

 

So it's working good?

 

No, it's working well.

 

It's working GREAT! ... But, we haven't had any really hot weather yet. Very muggy and a few pretty warm days, but no 95-98 degree stuff yet. Still, the cabin cools way more quickly than before and the fan speed drops to minimum almost right away.

 

Its the same on my 2012. The A/C always lights up when I hit the auto. However, I can turn that off in settings and keep it manual.

 

Sounds like there's both versions of behaviour, from the factory, maybe different years, and/or different countries. With our 2010, pushing Auto does not turn AC on.

 

Yes, it's a preference setting whether AUTO always enables A/C or not. Mine is set to not.

I did notice today that the manual setting actually seems to mean the last A/C state is remembered while the system is off. I pressed OFF this afternoon for a while because I needed the car READY but wasn't going to be in it, and later when I pressed AUTO again, it turned A/C on because it had been on before. Another thing that might figure into what different people are seeing.

-Chap

 

2011 Prius II 88k miles. Seattle area car whole life with AC rarely used maybe mostly defog. AC doesn't blow cold air at all. Here is what I've diagnosed so far

- No Techstream codes
- With AC on (AC button light on, fan on max, temp to LO)
HVAC fan blows fine on all ports
Condenser fan running
AC compressor makes normal noisy whine sound (higher whine when ECO to Power)
- Have not done the following
Look at sight glass results or felt temp on high low pressure lines during AC on/off operation.
I suppose Techstream should be able give reading on high side pressure sensor, haven't read it.

There is a coat of oil on the high pressure line from the firewall. Exhaust side of the engine is clean and oil free (head all the way down to exhaust manifold heat shield) Prius engine does blow back some debris settling along various crevasses.

Engine side facing passenger wheel looks clean from head all the way to the crank pulley.

Was wondering a couple of things

1. Do other gen3's high pressure line look clean coming out of the firewall?
2. Likely the o-rings failed at the firewall?
3. Are there really that much oil in the AC system that can leak out and coat the high pressure lines shown in pictures below?

Attached are some pics

- firewall picture is where high+low pressure line exit the firewall.

- highline from firewall picture is the high pressure line from firewall snaking its way towards the pressure switch assembly. It slopes downwards after exiting firewall so any oil will run along this line towards passenger side to the lowest point on the line.

- highline from switch picture shows the high pressure line making its way up to the block containing pressure switch. The dirt on the line immediately below the pressure switch assembly appears to be just air circulated dirt from front of the engine coming in from front of engine. There is no leak at all around the pressure switch, sight glass, and high port.

- pressure switch picture gives a good look at the whole switch, sight glass (I wiped off the dry dirt off the glass) and high port.

Here is the part diagram for the high pressure line (part 13)

Condenser, Compressor & Lines for 2011 Toyota Prius | Toyota Parts

 

What did you see?

From your pictures, my first theory would be that your refrigerant leaked out of the high pressure sight glass assembly and sprayed the line that's covered with gunk and everything behind it. If so, that's a relatively cheap fix compared to a bad compressor or evaporator.

 

I wonder could it have been over-pressure recharged some time in the past? Gasket(s) failed?

Took a look at ours: everything is clean.

 

You live in the pacific north west. Do you run your ac often, once a day, 2 times a week? If not, letting any ac system in any car go unused for weeks/months on out can lead to leaks. When the compressor does not cycle ac refrigerant/oil, you will get dry spots in the system creating o'rings to dry up and leak.

Ac gauges and checking high and low pressure lines for temp split is in order. I bet all your refrigerant is really low. Rocks hitting the condensor in the front is also another source for leaks. You will destroy your compressor without oil or refrigerant in it.

 

Haven't looked at sight glass behavior yet.

The oily residue on high pressure line appears mostly come from the firewall and ran along the line downwards until the low point. Lowest point is all the way to the corner of the engine on passenger side just before the line turn upwards towards the pressure switch assembly.

The residue on the vertical high pressure line exiting the pressure switch sight glass assembly is mostly dirt with just a hint of oil. The pressure switch assembly has a coat of dust on it but nothing feels oily.

So I might have a bigger leak down by the firewall and a smaller leak up by the pressure switch assembly.

Never charged in the past. Owned the car since 1K miles.

Thanks for the confirmation normal car's pressure lines are clean. Gives me a reference.

This is wife's car and she never runs AC so I suspect it only gets used on defog operation ('m guessing she doesn't even do much of that). Read your past post and indeed worried dried up o-rings might be the issue. And indeed if all that oil is from the AC system, don't want to be running the compressor for any length of time.

Did rudimentary pressure test by pressing on the low side port valve and got pressure that sounds like similar to 30+ PSI tire valves. But yes, more precise measurement is in order.

Inspected the condenser from front bumper opening and saw no obvious damage. Not a proof of course.

 

If the system is not running, the low and high pressure sides will be the same -- somewhere between "low" and "high." Either way, the hiss just means that the system isn't completely empty. Someone who know how the system works should put the gauges on and get the readings. And the gauges should have only been used on hybrid car systems to avoid contaminating your car's system with the wrong oil.

If the seals have dried out from lack of use, I would think that would be really expensive. A few years ago we had to replace the compressor AND evaporator. That was the most I ever spent on a car repair and I've been driving for over 45 years.

 

Don't conflate "hybrid cars" with "correct oil". There's probably hybrid cars with conventional AC oil. Safest bet is Toyota dealership service, hopefully they're on the ball...

Here's a screen grab from the Repair Manual, and I think it has a typo. I believe the correct oil to use IS ND-OIL11??



Here's a bunch of Repair Manual excerpts; I really should consolidate them. FWIW:

 

Good point!