lyh_chnxm Posted July 21, 2010 Share Posted July 21, 2010 I have a 05 subaru 2.5i with manual AC and i noticed that A/C is blowing warm-cold air for 15 seconds and cold-cold air for another 15s. In the video you can hear the compressor is on and off for every 12-13s Is it normal on Subaru? As i know my friends' honda and mazda their compressors are working unless AC is turn off. [ame=http://www.youtube.com/watch?v=07tNuRNmlZ0]YouTube- 07202010035.mp4[/ame] Link to comment Share on other sites More sharing options...
jranmann Posted July 21, 2010 Share Posted July 21, 2010 If this bugs you enough to spend a few bucks on it (and it would me!) I would have your AC system checked by a pro for refrigerant level (too much 'freon' or not enough) Mechanically it's hard on the clutch (and thus your AC compressor) and also (CLICK) draws alot of current flow...back and forth continuously which, is by definition never is good thing to ignore but not of huge concern... btw: Was the AC system recently charged up for the summer? Your symptom (showing first warm then cool then warm) might be simply a matter of flushing and then recharging the system or a slight electro/mechanical adjustment...frankly it sounds like the expansion valve (between the high and low pressure sides) is detecting an anomaly (fluxuating pressure difference?) and likely as not the refrigerant has gotten air bubbles into it it over time. Perhaps your environment is super humid, etc or a seal on one of the hoses has been leaking slightly...It doesn't take much and now that it's hot again, you are using the AC more frequently. These systems work at very high pressures...Not quite as high as say the BP oil well in the Gulf of Mexico of course...but it's up there! Say, do Subaru's have a sight glass (porthole) on your reveiver/dryer, used for a visual inspection? (Very top of page 9 here: http://www.endwrench.com/pdf/heat/FtACSystemsS98.pdf) Usually it takes a high/low pair of manifold pressure gauges to accurately monitor the flow...but a quick and crude test can be done with that glass (eye into the system) cleaned and if it's showing massive (or any) frothy bubbles traveling past instead of perfectly clear and colorless...then you know there's something amiss and likely there's some amount of leakage somewhere...hence the leak test he will do for you first off. By the way lyh, your creative method of using visuals here of your engine running and the graphics is a fantastic use of this medium and I compliment you most highly on your most demonstrative way of making your point and showing your issue so clearly to everyone...Good job!...and good luck! Ran Link to comment Share on other sites More sharing options...
RJS5689 Posted July 21, 2010 Share Posted July 21, 2010 Go search, this issue was just discussed in depth. Link to comment Share on other sites More sharing options...
jranmann Posted July 21, 2010 Share Posted July 21, 2010 Go search, this issue was just discussed in depth. Hey some people just need a map?...Given my fairly relevant link posted would you mind showing him where else, via the same method...? Cheers! Link to comment Share on other sites More sharing options...
bighaus90 Posted July 21, 2010 Share Posted July 21, 2010 http://legacygt.com/forums/showthread.php/c-fluctuates-between-warm-and-cold-140657.html?t=140657 Link to comment Share on other sites More sharing options...
stiwanabe Posted July 21, 2010 Share Posted July 21, 2010 sounds like your low on refrigerant. Its normal for the compressor to cycle on/off but you shouldnt notice a change in temp. Link to comment Share on other sites More sharing options...
lyh_chnxm Posted July 21, 2010 Author Share Posted July 21, 2010 Hey guys, the post is for auto AC, and mine is manual AC which has different system and setting back to topic Ran, thanks for your suggestions, i dont think this generation equips sight glass, and I did went to let pros check it. However when i got there, everything was working again:mad: Today I went back to workshop. This time they saw the problem and said it maybe cause by low pressure so they recharged the system, but the problem still there. After few tries, we found out a very interesting thing. When the circulation is on and set fan speed to 3 and 4, or circulation is off with fan speed equal or larger than 2, the problem will go away. Here is the chart Fan Speed - W/ circulation --------- W/o Circulation 1 ---------on and off every 12-13s -- on for 40s and off for 20s 2 ---------on and off every 12-13s -- Normal 3 ---------Normal ----------------------- Normal 4 ---------Normal ----------------------- Normal They told me probably the computer is controlling the temperature, even though it is a manual system. When the fan speed is 1, if compressor keeps working, it will produce too much cold air, so computer will turn it off automatically. On the other hand, when the fan speed is greater than 2, even compressor is fully loaded, it still cant meet the requirment set by the program in the computer. Therefore it will keep working unless you are driving uphill and engine may draw more power from AC system. They recommended to set the fan speed greater than 2 and turn circulation mode off in order to extend compressor's lifetime. Any thoughts? Again, Ran, thanks for helping me to figure out the problem:lol: Link to comment Share on other sites More sharing options...
suby08 Posted July 21, 2010 Share Posted July 21, 2010 I have an 08 with the same warm-cold-warm-cold symptoms. After 3 visits to the dealer, they finally changed the refrigerant saying there was 4oz in there instead of 8oz. They filled it and said i was all set - now it was very cold-warm-verycold-warm. So after some calls to the 1-800-subaru-3, it was escalated to a manager. They have had my car for 6 days now, and say its pretty much all set. When i asked what was wrong, i was told they replaced the refrigerant again (??). We shall see how it goes. Link to comment Share on other sites More sharing options...
suby08 Posted August 11, 2010 Share Posted August 11, 2010 Update: Its been a month since the dealer had my car. They have since changed the condenser saying they suspected a restriction in there. No difference. When i pushed the issue, they sent a field rep to see the car - they pronounced it as "fixed" even though the car was acknowledged as having the symptoms. I asked to be there when this field rep arrived but no one called me, and he mysteriously came and went. I was told there was nothing more they could do. I somehow managed to escalate it to the executive offices who allowed a reversal of the decision and said i could get a second opinion - they would cover the cost of the diagnostic and a rental. Turns out, the vehicle is performing as designed, and the service manager even said it was annoying and even he would be unhappy, but the car is only performing as designed. A laptop hooked up to the system while driving, showed the warm cold cycle was directly linked to the compressor cycling - why its so noticeable in the 08 Legacy is beyond him, but it is how it was designed. I"m going to try and cover up the solar and temp sensor in the cabin, this will hopefully prevent the system from cycling as often - not the best fix, but so long as it prevents this cycling thats all that matters. Guess its a really really bad design Link to comment Share on other sites More sharing options...
MoscowLegacy Posted July 21, 2011 Share Posted July 21, 2011 my girlfriend has an 07 legacy na and now that it is summer time we use the ac practically everyday. I noticed the compressor turns on and off constantly too, although the temp does not fluctuate. I am aware that obviously the compressor on any car cycles on and off but the short time in between that my girlfriends car does it is VERY annoying. So annoying in fact that I turn the AC off when idling for more than a minute or two. Link to comment Share on other sites More sharing options...
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