:confused:

02 WRX Sedan with about 12k miles

Now that the summer heat is here, I?ve discovered a problem with the A/C Ventilation system. After about an hour of driving in hot weather with the A/C on, the air flow coming out of the ventilation systems diminishes to nothing. Even with turning the fan speed up to 4, hardly any air flow can be felt from the vents. Adjusting the air flow location (floor, dash, or windshield) and turning the A/C switch on & off doesn?t fix the problem. In order to get normal air flow back, the car must be shut off. I?m guessing there is a vacuum line problem, either a pinched line or leak somewhere which is causing all the vent routes to close. Once the car is shut off and restarted the system builds pressure again and functions normally for another hour or so. Since this problem didn?t show up during the winter, I?m guessing it is related to the A/C usage. I was wondering if any one has encountered this already or if anybody has any thoughts where I should begin hunting for the problem.

Also, can anyone share info(route diagrams, etc.) on the vacuum and ventilation systems?

Any help is appreciated.

Next time it stops blowing air, pull over, and pop the hood. I'll bet you see ice (yes, ice!) on the a/c lines.

From your desciption, it sounds like your a/c is freezing up. It can be caused by your system having too much or too little R134a, or a bad theromswitch. Take it in and have it looked at.

That said, mine does the same thing, and as of today my local dealer had been unable to fix it. SOA is coming to look at my car tomorrow, along with another car that defies being fixed.

Flakey a/c + South Texas heat = Unhappy Driver (me)

Unhappy Driver + Unfixable (?) WRX = No More WRX! :mad:

Thanks for the tip. Please post what you find out after the SOA rep looks at your car. I'd like to have as much info as possible before I approach my dealer's service dept.

I too ran into your AC problem. I live in Northeast Florida and have only had it happen once. The time it happened was when I had been traveling at highway speeds for about 2 hours and then got stuck in bumper to bumper traffic due to an accident. I was able to restore airflow temporarily by turning off the AC for a few miles and then back on. After cycling through that process several times in a span of 30 or 40 miles at regular highway speeds, it finally stayed on. I was told by my dealer that it is a defense mechanism the car uses to prevent overheating and there was nothing wrong. Like I said, I live in FL and have only had the problem that one time.

I was told by my dealer that it is a defense mechanism the car uses to prevent overheating and there was nothing wrong.

Sounds like a typical dealer BS to me!:D

Add me to the list with this problem...has happened 4 times, typically after running about 3 hours at 75+ mph. Haven't had a chance to approach the dealer, I tend to support the ice theory given the abnormally large pool of water under the car after parking it. Hopefully my dealer won't give me the "can't reproduce problem" answer since it takes 3 hours to create it!

If it takes that long for it to ice up then drive it around and take it to the dealer when it stops working and have the manager look at it.

Do any of you have the air filter installed? If so pull it out and have a look at it.

p@

Originally posted by rss600
:confused:

02 WRX Sedan with about 12k miles

Now that the summer heat is here, I?ve discovered a problem with the A/C Ventilation system. After about an hour of driving in hot weather with the A/C on, the air flow coming out of the ventilation systems diminishes to nothing. Even with turning the fan speed up to 4, hardly any air flow can be felt from the vents. Adjusting the air flow location (floor, dash, or windshield) and turning the A/C switch on & off doesn?t fix the problem. In order to get normal air flow back, the car must be shut off. I?m guessing there is a vacuum line problem, either a pinched line or leak somewhere which is causing all the vent routes to close. Once the car is shut off and restarted the system builds pressure again and functions normally for another hour or so. Since this problem didn?t show up during the winter, I?m guessing it is related to the A/C usage. I was wondering if any one has encountered this already or if anybody has any thoughts where I should begin hunting for the problem.

Also, can anyone share info(route diagrams, etc.) on the vacuum and ventilation systems?

Any help is appreciated. your evaporator drain tube is clogged allowing the water to freeze on the evaportor making your AC stop working...take it in and get it fixed pronto...can evually cause damage to the compressor.

i know we had the issue on the '01 civics...the plastic drain tube was molded wrong and was blocked off, but with honda's there's an access panel that was low enough that the water just poued on the carpet rather then allowing the evaporator to ice over.

jeremy

WRXdude,
Any word from the SOA rep yet? I haven't been able to reproduce the problem these last couple of days. The next time it happens I'll look for ice on the lines. Thanks

Akiata wrote:
"Do any of you have the air filter installed? If so pull it out and have a look at it."

Yes, I have the air filtration "system". I pulled the filter today to check the condition. Moderately dirty with a few leaf bits and acorns in there, nothing that would stop the air flow though. What were your thoughts on this?

Jeremy,
I looked over the drain tube today. I don't think it is clogged or pinched. I traced it from the evap core to the end but couldn't see or feel anything wrong. The inside diameter of this tube is pretty big so I don't think blockage should ever be an issue.

Also someone please verify that I was tracing the correct tube for the evap drain. The picture below shows the tube just to the right of the date Jan 25 2002. Yes?

Thanks,

I had the same problem, but only when I had the selector on recirculate. Move it over the other way and I havent had it happen again since.... Now it sounds like whenever the compressor kicks on it sounds like the belt slips for a split second, kinda sounds like there is a damn bird under my hood or something....

Happened to me twice, the last time just a couple days ago. Both times, it's on long road trips after using the A/C for many hours, and at very high ambient temperature. Turned off A/C for a few minutes each time, and it's okay after that.

Will mention it to the dealer tomorrow as I'm getting an oil change. I will report if they have some insight. I doubt I can really reproduce the exact symptom at a dealer.

One thing to keep in mind is that it's the AIR FLOW that's blocked - not even fresh air from the vent. All I get is fan noise; and the symptom is progressive. Since it goes away after several minutes, I also think there's probably due to ice building up.

Finally, both times, it happened when the vent is set to fresh air.

-Ray

Well, I don't think there is ONE problem with these cars. I didn't know until last year that the refrigerant isn't factory installed. Its either dealer or port installed. The doofus charging the system may or may not have known what he was doing and thought "what's a few more/less ounces of refrigerant?"

If you have the air filter installed and your system was slightly overcharged/undercharged the restriction from the air filter may be just enough to ice up the coil. Or if you have too many supply vents closed you can ice up the coil.

Does anyone know when the switch is set to "fresh" does it pull in 100% outside air or does it still use some cold air from inside the car? The air going back in the return duct may be too cold and iceing up the coil.

The compressor may not be shutting off. I actually don't know how auto AC's work and what kind of controls they have but on my car the compressor cycles on and off. It's probably doing this because either the its sensing the refrigerant temp getting too cold and protecting itself or the temp in the car is cool enough.

I don't know what kind of metering device they have but if it is too big (someone ran out of the correct size and use the next size up) it will let too much refrigerant into the evap and ice it up.

I have a chapter of automotive air conditioning in my refrigeration and AC book. I will read it soon but don't have time right now. Maybe this weekend.

p@

Originally posted by Usacjudge
I had the same problem, but only when I had the selector on recirculate. Move it over the other way and I havent had it happen again since.... Now it sounds like whenever the compressor kicks on it sounds like the belt slips for a split second, kinda sounds like there is a damn bird under my hood or something....

I have gone through three A/C Compressors (1 original, 2 replaced) and the same problem occurs.

I have been to three dealerships here in Orlando and Tampa and all don't know what it is.

-The original compressor was started making a loud REALLY LOUD chirping or screeching sound and when it did that the car would like buck forward and back a little. A/C Compressor Replaced due to dealer saying compressor clutch is misaligned.

- 2nd A/C Compressor - same problem started occuring after about 1k miles. Took it to dealer, they recharged the a/c to specs and still making same problem. Result: recharged and still having same problem, misaligned and was replaced under warranty.

- Now on my third A/C compressor...I have not used the A/C as much being scared that it will go bad again, but with this rain and weather in FL, it makes it a necessity. Problem occurs but not as loud.

I took it to a dealership in Tampa and they called the "SubaruTECH" hotline:lol: and all they could advise was to recharge it, checked the tension of the belt, but the same symptoms occur.

One way to make the dealership hear the noise is rev your car in idle keeping it at about 3k RPMS, a/c turned on to setting 1, wait till the a/c kicks on then when it kicks out, you may hear that screeching noise.

I did this demo to the dealerships I've gone to and they are clueless.

This is my story and pending...this a/c problem is really convincing me to get a nissan cause I cannot live with this back and forth from the dealership life.

I love my car, but this problem has been occurring since 29000 miles on my car with now currently 38000 on it.

Kevin Tinoco

Well, when my car goes in for the oil change tomorrow I may do the demo you speak of to them and see if they can figure it out. At least I know I'm not the only one having this issue. Mine doesnt seem to be as violent as yours, mine truely does sound like a bird chirping as opposed to a screeching noise, and I do feel a *slight* hesitation when it happens so I am thinking the belt may be loose... Guess I (may) find out tomorrow.

I've had the same problem. On a recent drive up to L.A. from San Diego, the AC stopped flowing cold air. Air was still coming through but it was not cold. After that, I turned it off and cracked opened the windows. A few minutes later, ICE was coming out the vents followed by water a few minutes later. After about 10 minutes or so, I turned the AC back on and all was great after that.

Let me know what the dealer tells you guys. I may need to go see one soon, too.

all cars react differently...but I would imaging if you hear that damn bird coming out your engine bay, you should be able to let them hear the problem revving the car to 3krpm and maintaining it until you hear the a/c cycling on and off.

One thing I did notice about my car that it is much colder air than the other cars that I have been in.

Keep us posted

Kevin

Been there done that. The Coils are freezing up. Simply put your temp one or two clicks up from full cold and use the fresh air setting if you are going to be on the highway for a long time. It will never freeze again and the air is ice cold.

CT

Talked to the service manager at the dealer today while I was getting an oil change. They checked it, and agreed that it's condensation freezing up. Not sure if there's anything we can do about it. Have the same problem later today, a very humid day in New England.

I have a different take from some of you here though. All three times I was using the "fresh air" setting for the vent. Which makes me think... Ain't I actually getting moisture from the atmosphere by using "fresh air"? Shouldn't there be less condensation if I'm using recirculate?

I'll keep an eye on this, and report again later.

-Ray

I have also experienced the same problem. I have always had it on fresh air, and it always happens after long drivers (highway speed). The air is still very cold, but its barely flowwing through the vents. I have installed an air filter so I was wondering if I installed it wrong (not that there are many ways to install it), but since the airflow is reduced so much I was wondering what could be blocking it. It sounds like the fan itself is blowing like crazy, it just doesn't come out of the vents. I will probably pull the filter next time it happens, maybe its freezing over?! If I shut the car off for a short while it disappears (I did try driving with the heater on for several minutes, but this didn't fix it.)

Maybe the solution is to drive without the air-filter in the summer, and turn up the heat slightly from full cold!??!

-anders

Originally posted by aov
I have also experienced the same problem. I have always had it on fresh air, and it always happens after long drivers (highway speed). The air is still very cold, but its barely flowwing through the vents. I have installed an air filter so I was wondering if I installed it wrong (not that there are many ways to install it), but since the airflow is reduced so much I was wondering what could be blocking it. It sounds like the fan itself is blowing like crazy, it just doesn't come out of the vents. I will probably pull the filter next time it happens, maybe its freezing over?! If I shut the car off for a short while it disappears (I did try driving with the heater on for several minutes, but this didn't fix it.)

Maybe the solution is to drive without the air-filter in the summer, and turn up the heat slightly from full cold!??!

-anders

Its not the filter. Its the Evaporator freezing up. The fan can no longer get any air. The solution is to put the temp control a few clicks up towards heat. Try 2-3. You will be introducing a small amount of dry hot air which will prevent the ice over. The air out of your vents will be ice cold as normal and it will blow without freezing.

Try it guys...

CT

Well, my car is at the dealer now, I will let you guys know if they find anything out....

Sorry, but I tried the "turn it up a notch or two" trick" to stop mine from freezing up. Same thing happened, on fresh air or recerc.

Update on my car- still at the dealer, still working on it, no parts list yet, but I hope they're doing *something* about this persistant problem.

To quote my Dad (engineer) and a buddy (auto engineer), "This isn't rocket science! Why can't they fix it??" I agree - automotive a/c is a well-understood artform (it's been around over 60 years!), and pretty basic. I know that my dealer had mentioned that they want to replace my condenser, reciever/dryer, orfice tube, evaperator, and a newly designed thermoswitch located in a new position - but not the compressor. I don't think that the compressor is the problem, so I'm OK with that. If, after all of this work, it still does freeze up, I'm going to get pretty testy about it. I'll keep everyone posted!

AZScoobie - makes sense. forgot about that possibility.

-anders

I will add my 0.02$! In my case, it is a fan that makes whistling soulds (like a leaf is in the system). I used A/C a lot yesterday and the day before (when it was quite hot in Oregon!) and today I noticed that my passenger side carpet is drenched!!!!!!!!! I had the same problem with my '92 Civic... sounds like a clogged drain tube for me... Called the dealer and the guy seemed clueless :rolleyes: . I have to wait until Monday to have it checked... good thing it is not going to be hot this week-end here! Oh well...

Jess

Well, they got rid of that pesky "bird" I had under the hood. They tightened the belt and all is good again. Now wether or not it stays fixed is another question. Hope you guys get your problems sorted out....

Well, I got my car back after 3 days. All they ended up doing was relocating the thermoswitch. Not even the newer designed one was installed - just moved the one I had. So far, it hasn't frozen up. I was told that they got a lot of good data from my car, and that it would help with future repairs and redesigns. That's all well and good, but is my car fixed??? Nobody seems to know if this will fix it. Grrrrrrr!

When I got the car back, the gas was full, but there was a SERIOUS amount of miles that had been put on the car, it was filthy, covered with squished bugs (some look like they died at high speed!), and I got it from a 3rd party that my car got "beat on" by the SOA engineers, the engineers in from Japan, and Calsonic's people. They had used the stereo, and the ECU had been reset, thus erasing any evidence of their missdeeds in my car.

I did get a customer satifiaction follow-up call from the dealer, and I will return it tomorrow. I will also follow up with SOA- I am outraged by the treatment of my car by these so-called professionals!!! :mad:

Welcome to the party, gang.

Yep, these are the same problems that a bunch of us have faced since 1st allocation cars from March '01 (of which mine is one). Mine was one of the very first ones in the nation that was tackled last year. (Do a search and you'll see tons of talk about this from last summer.)

First, the dealer checked the charge and found that the system was overcharged, which they fixed. Still had the problem. Then
SOA and Calsonic replaced the entire AC system in my car, and the freeze-up still happened. After that, they relocated the sensor(s? -- not sure which one or how many). Then it was autumn and too cool out to reproduce the problem.

I just drove 2000 miles thru 90F temps and 70F+ dew points last month (the identical conditions that previously caused freeze-up), and the AC worked perfectly the whole time. It looks like relocating the sensor was the only thing to make it work properly.

I'm disappointed to hear that they haven't shared this solution nationally, and that they are still building cars with this problem, and that the engineers are still scratching their heads.

WRXdude, all I can say is that it worked on my car, so I would hope that it would work for you.

Mine hasn't frozen up - yet. I'm expecting that it will at any time though. <sigh>

:mad:

So there is actually a fix for this now? Does anyone have any specifics on which/where the sensor/sensors/thermoswitch are located and where they moved them?

I haven't experienced the problem this summer yet but it has been unseasonably cool here and I haven't been on any long drives with the AC on.

Good luck fixing it guys. If you do get a fix make sure to post it. For now its not a big deal as mine does not freeze up if I turn up the heat a bit. Plus, since I have owned Audi's in the past and just today drove a Friends S4 all over town I like my Scoobs AC. In an Audi your AC does not work at idle in the summer :) Nothing like sweating in a $45,000 car wearing business clothes at a stop light.

CT

I fixed my a/c! It was easy as trading it in for a 2003 Infiniti G35. No more problems with my WRX's a/c. It'll be someone else's problem.

To answer the question that is in everyone's mind- it wasn't just the a/c that made me dispose of the WRX- continuing issues around the clutch/pressure plate, customer service issues, and lastly a newly-developed surging issue added up to make me jump ship. Remember, my experience with it shouldn't deter others from getting one. I had one of the first cars in the US - maybe one of the first 10 people, and have one of the lowest build #'s. Later cars don't have the same issues as my car had.

Will I miss the WRX? I sure will. Do I regret owning it? No! I loved that little car, but it all became too much for me.

There's a couple issues being discussed here, but I think the main one is the core freeze up. Search the archive for last summer's discussion.

AZScoobie: your idea of turning the temp dial slightly warmer will not fix the problem. The way an HVAC case is designed is such that ALL the air goes through the evaporator coil regardless of temp door position. Then, AFTER the evap, the temp door/dial allows a certain amount of hot air to be blended back into the chilled air to attain a desired discharge air temp at the outlets.

The fresh/recirc control may seem to be important, but it's really not. In recirc, you're feeding much colder air into the evap, so it may be more easy to freeze it. In fresh, you're feeding much more humid air into the evap, so it also (under the right conditions) may be much easier to freeze it. It all just depends.

The compressor cycling is controlled by a temperature sensor that's jammed into the evap core. The engineers study the core to figure out the coldest spot, and that's where they put the sensor. When the sensor reads near freezing, it cuts the compressor to keep from freezing the core. Usually, this cycling happens between 3 and 4 degC (OFF at 3, ON at 4). Now, if you accidentally put the sensor in a spot that's not the coldest, then the coldest spot may get below freezing temps. Condensed water will freeze into ice at that spot. The ice blocks airflow. The reduced airflow causes the evap to get even colder, and the sensor to (usually) read warmer. This failure spiral results in a big block of ice under your dash.

Relocating the sensor is the best solution, after you've confirmed that your A/C charge amount is correct.

Rob W.
Senior Climate Control Engineer

I'm glad I found this thread, because this happened to me last week on my way to Pikes Peak. I found the most comfortable was to deal with it was to turn the AC off, leave the fan on 2 or 3, and keep going. In a few minutes the air volume coming thru the vents will increase and get warmer , you can then turn the AC back on and it's good as new, for a while.

I'll bring it up next time I take it in, and as long as it doesn't happen while stuck in traffic, I'll be OK with it. But if it soaks the floor I'll be ticked.

Hi! It turned out like I thought, my drain tube was clogged or kinked and that was why my carpet was wet, just like in my previous '92 Civic. I will keep my fingers crossed for no more A/C problems :p .

Jess

This happened to me last night during a long drive through Ohio, WV, and VA.

I noticed a few other things that fit with the ice explanation.

1) It started to smell like a freezer

2) I started flailing around and moving every control I could to get it working again. I noticed that the temperature control wouldn't go all the way to hot. If I held it over, it would just jump back to about 4 o'clock on the dial.

And, as one would think with an ice problem, this morning it was fine.

Do you think this is worth bringing it in?

I made an appointment with the reluctant service manager. He said, "this just happens," and suggested that I just pull over and wait for it to thaw.

On a long trip with an 11 week old and a 19 month old, I don't think I'm going to do that.

Since when is it OK for an air conditioner to flake out just because it's a long trip.

He is young, I don't think he really knows what he's doing. The appointment is in 3 days or so.

What do you think, should I go another round with him or get in touch with SOA or what?

I'm a little late in the game, but I thought I'd share some opinions that I have.

First, if you have that cabin filter, take it out. If there's the slightest amount of dirt in it, you're screwed and it just impedes airflow.

Second, I had the same problem on my old 1.8 Impreza. During Florida summers, I would have to stop once every three hours for about 10 minutes and just watch it drain a gallon of water...literally! I'd get a few drops under the dash, so I'd know it was time to pull over. The car ran fine, but once I got outside of Florida where it isn't flat, I noticed how much it affected the performance of the car and how much power it took away.

Now, I have a '01 RS and I have not experienced any of these problems in almost 72000 miles of driving. I've had the a/c on during several non-stop trips of over 12 hours. It never gets hot in the car nor do I have compressor issues or temprature variances. During this time of year, the car just pees water constantly when its 90+ outside with a 77F dewpoint.

I also have a '90 Legacy and an '02 OBS which should also be an early build model. No problems on this car either.

However, I have observed a/c problems with friends that own WRXes. It never seems to be as good or efficient as any of my n/a cars. Going out on a limp, I'd say that the a/c taxes a smaller motor, plus there's a ton of heat that is being generated by WRXes. When in my friend's car, we have to use the recirc option just to keep it tolerable. In any of my other cars, I can use either option and its still comfortable. If you can get your windows tinted within legal specifications, I recommend that too. My wagon and Legacy aren't tinted, but my RS is quite dark and it certainly helps.

Also, remember that the a/c system will have to work twice as hard when you have it set to fresh instead of recirc because it must cool and dehumidify outside air. Recirc allows the system to just work with what's in the car. I use this in traffic or when I first get in the car. I don't use recirc all the time because it will smell "stale" after a while and I need to get some fresh air inside the cabin.

I don't know if any of this helps, but there're just some observations that I have.