Intermitten AC

[SVX95]

I was having a problem with the AC on my 95 SVX. It would work in cool weather 80< but when it got 80+ it wouldnt. I brought it to a subaru dealership and was told it needed a new expansion valve. While in the process of working on it they then told me the evaporater was stripped and needed replacement. $850 later the A/c works for the first 20 to 30 min blowing cold then it only blows just cool again and wont blow cold at all no matter how long the ac is on. Is this normal for a SVX. I have a 97 Legacy that always blows cold so i cant figure out if this is normal.

[TRCKRCR]

I have almost exactly the same problem! If it is over 80 outside the compressor doesnt come on. I think, but am not sure it may be due to engine tempreture and some sort of sensor telling the compressor to stop going on because the engine may overheat. I am going to try installing a cooler thermostat to see if that helps. Let me know if anyone else has an answer. Ken TRCKRCR@aol.com

[cdebban]

With this H.V.A.C. system there are alot of components that could make htis happen I suggest taking it to a dealership that has alot of experience with this system!

[Green1995SVX]

mine does the EXACT SAME THING!

M

[lee]

Since your problem seems temperature sensitive, the first thing I'd check would be the pressure in the system. The high side pressure is normally about 2.2 to 2.4 times the ambient temperature (if I remember correctly). It doesn't take much freon to overfill, especially with 134 (it uses less than R12 for the smae capacity system). So, if somebody has added too much freon to the system you could be easily be exceeding the pressure limit at the trinary switch on hot days - which when it opens, cuts the current to the compressor clutch.

[northernkanuck]

Try cleaning out your condensor. The thing in front of your rad that actually looks like a rad. It can get clogged with road dirt and grime and not allow enough air flow causing the system to kick out on high pressure. Take it to a self car wash or use a high pressure washer (be careful how you aim the water at the fins or you may damage them). Once the condensor is cleaned out it will allow more air flow and take care of your problem. This would be your first and least expensive step to try and resolve the problem.

Keith

[Green1995SVX]

Could it be my big tranny cooler in front of the condensor blocking the air?

-Mike

[maximvsv]

Originally posted by SVX95
... then it only blows just cool again and wont blow cold at all no matter how long the ac is on.

I have the same problem. I noticed that mine will provide cold air if I back down the fan to medium or low.

[greenSVXer]

I had the same problem: It was the right fan that wasn't working because a burned fuse. It seems that when the temperature rises, the pressure rises and the system shuts down. Both of your radiator fans have to be working at the same time...

[Earthworm]

Another possibility could be moisture in the A/C system. This moisture could freeze and cause the A/C to stop until it melts.

Another indication of A/C issues is by observing the glass eye on the dryer. It should be clear when the A/C is on and not bubbling or foaming.

[1994SubaruSVX]

friends and my air conditioner would not blow cold no matter what i did. i took it to my mechanic and he said it could be a variety of sensors. told me he would have to take the dash out??!! anyway just yesterday it was like 97 degrees so i decided to give them damn thing a shot and it came right on and blew cool??:confused:

[Boone]

If you are overheated or the climate control thinks you are the compressor won't engage. How healthy is your cooling system? ;)

mebbe try the diagnostic next time?
http://www.subaru-svx.net/photos/files/Boone/3861.txt

[SVXRide]

Here's another twist - my '92 (with a newly installed compressor) will run cold then blow warm/damp air, then blow cold again. I do get a major "gurgling" sound from the radiator overflow tank when I shut the car down. Any suggestions as to other things to check (other than those already listed in this post)? Thanks

[Earthworm]

When they recharged the A/C did they vacuum the system?

[SVXRide]

Don't know, I'll have to check. Thanks.

[SVXRide]

Boone - Thanks for the diagnostics! I ran it both after the car had been sitting in the shade for a while (okay, I was waxing it...) and then after I had driven it around the neighborhood for about 10 minutes. First time it just gave me a TEMP188 followed by 00. After the short drive it gave me a TEMP188 followed by a 13. Now, I parked it in the shade after the drive, so how does this factor with an "open" sun sensor? Still working on whether the system was vaccuumed when the new compressor was installed...

[SVXRide]

Earthworm,
Just checked and they did vacuum the system when they installed the new compressor. Also found out that they filled the system with 134 (and used 134 oil). The guy who did the work thought that maybe the condensor is clogged?

Question to all - Lee mentioned earlier in this thread that the trinary switch might be cutting out the compressor if the pressure in the system gets too high. Anyone know exactly what the high side pressure should be when you use 134 in a '92?

[Boone]

I guess the "13" is normal when you're in the shade. ;)

[vkykam]

Huck369 fixed a cooling issue on Zeppelin's car during the meet, and if I recall correctly Zeppelin had put in the R134a retrofit stuff into his 92. As it did turn out, Zeppelin had too much R134a in the system.

VK

[lee]

The code 13 shows up when sunlight (or a 100watt bulb at 1 foot) isn't used over the sensor. no biggy, just check in the sun.

As to pressure, with a new compressor and drier, and using 134, my system showed (on low & high sides respectively - all in PSI)

at idle 33 and 185
at 2000rpm, 26 and 215

The trinary switch will cut out the system around 380psi (high side of course) and won't allow it to turn back on until pressure drops to around 213. Refrigerants are funny things in that they build excess presssure quickly with overcharge, and are directly dependent on external temp. So a somewhat overcharged system could work in spring/fall and fail in summer.

[SVXRide]

Lee,
thanks! What was the ambient temperature when you took your pressure readings?
-Bill

[lee]

ambient = 82F

the vents pumped out at 46F after about a minute @ 2000rpm (didn't take a number at idle).

Near as I can tell it's the original condensor, evaporator, expansion valve and hoses (judged by appearance only, I purchased SVX in late Feb, changed compressor late June).

For those comparing, that's on 134, remember R12 number should be different.

[SVXRide]

Lee,
thanks! Now I just need to get it to a shop with the A/C gauges...
-Bill