rcrooker Posted October 1, 2003 Share Posted October 1, 2003 Got a 2003 OBW, 5 speed, 4 cyl., in June. Great car to drive except with the a/c on below 40 mph or so, I can't keep a constant speed. Trying to do so, the car will lurch (i.e., slows down, or speeds up, abruptly) with the least let up or pressure on the accelerator. Annoying on smooth roads, but bumpy ones accentuate the problem (since it's harder to keep constant pressure on the pedal). The problem goes away when the a/c is off or when the a/c is on AND the car is not warmed up (idle speed about 1300). I can minimize the problem by driving in a higher gear, but that's no fun; nor i Why does this happen (especially since only with the a/c on)? and why does it not happen when the car's cold (does this suggest an adjustment to avoid the problem?)? I'd like to get this fixed before next summer! Quote Link to comment Share on other sites More sharing options...
RallyKeith Posted October 1, 2003 Share Posted October 1, 2003 What have the folks at Becker had to say about it? I'm guessing it's just the clutch on the compressor engaging and disengaging and you're feeling the loss of power when it engages and the gain of power when it disengages. If you want to test my theory there should be a wire going to the compressor that controls this. Disconnect the wire and try driving the car with the AC on. If it still does it then it is something else and you probably should take it back to the dealer to let them experience it. Keith Quote Link to comment Share on other sites More sharing options...
rcrooker Posted October 1, 2003 Author Share Posted October 1, 2003 Keith- Thanks for the suggestion. I've had other cars where you can feel the a/c compressor cut in as a bit of a lack of power, and I'd notice this particularly at highway speed. In this case, though, I can feel the "lurch" forward when I take my foot off the gas (even a little bit), and then back (into the seat) when I reapply gas. I wouldn't expect the compressor to cycle (only) in concert with using the accelerator. Haven't been to the dealer yet - I wanted to hold off until I had some background on the problem, and hopefully could get to a solution more quickly. Regards, wongleflute Quote Link to comment Share on other sites More sharing options...
Sweet82 Posted October 1, 2003 Share Posted October 1, 2003 My 2001 Forester does the same thing:mad: It's obnoxious to drive with the A/C on :mad: Let us know what you find!!!! Glenn, 82 Hatch, no A/C 01 Forester, obnoxious A/C Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted October 2, 2003 Share Posted October 2, 2003 just a wag but I wonder if this might be one of those problems that are cured by turning off the A/C, then resetting the ECU, driving for a while with the A/C still off before turning it on? Like the ECU learned a bad habit? I've read it works for some weird tranny problems. Carl 1 Lucky Texan Quote Link to comment Share on other sites More sharing options...
rcrooker Posted October 3, 2003 Author Share Posted October 3, 2003 Glenn- Does your Forrester give the same lurching when the weather is cool? (e.g., when the defroster and a/c are on) I set up an appointment for the dealer (steve moyer, Leesport,PA) to look at it next week, and the conscientious service rep called back with "talked to head mechanic, who said that's normal, but we'd be happy to keep your appointment". So I still have the appt, but decided to demonstrate the problem to myself last night. Nada. It must have known it was going under the wrench. During the summer, every time (except for the first 10 minutes or so of warm up) the a/c was on, and I was driving at constant speed under 40 mph, it lurched with small changes in pressure on the accelerator. So have you seen the problem on your Forrester disappear when the outside temp goes below 60F? Carl- Is the "ECU" the car's computer? How do you reset it? Thanks all. wongleflute Quote Link to comment Share on other sites More sharing options...
cookie Posted October 3, 2003 Share Posted October 3, 2003 When it is hot the compressor kicks in more frequently. I once had a tiny rental car in Florida that bloody near stalled when the AC cycled. If it was a Mercedes there would be a software fix shortly, but this is Subaru. If your engine is lying on the ground they are likely to say what engine? At least from what I see on this board. Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted October 3, 2003 Share Posted October 3, 2003 The 'traditional' car computer reset procedure is to disconnect the battery for 15-30 miunutes. I think someone said there is a fuse you can pull that does the same thing. Reconnect and use the car for a few 'start cycles' without using the A/C, the cruise control, and try not to depress the accelerator while starting. These last 2 have been reported as causing problems. Might be worth a try - just a guess really. Carl 1 Lucky Texan Quote Link to comment Share on other sites More sharing options...
theotherskip Posted October 3, 2003 Share Posted October 3, 2003 i got some relief from this problem on an older (97) obw by cleaning out the throttle body. i used a throttle body and intake cleaner, available at napa and others, and cleaned it according to their directions. it didn't fix it completely, but it definatly made it much more controllable. my engine definately had a fair amount of carbon build up, so it may not help in your case... Quote Link to comment Share on other sites More sharing options...
Lesbaru Posted October 4, 2003 Share Posted October 4, 2003 My 86 GL did the same thing. It was dangerous, and scared the crap out of me. I'm cheap and tawdry, and just had the a/c disconnected completely. Quote Link to comment Share on other sites More sharing options...
rcrooker Posted October 9, 2003 Author Share Posted October 9, 2003 Interim update: Since I couldn't get the lurching to repeat itself when the weather was cold, I called my dealer and had a chat with the mechanic. Nothing they could do without the problem showing up and he wasn't familiar with the problem. I asked if resetting the ECU would help, he thought not, since the computer doesn't interact with a standard (stick) transmission (but he did say constant shifting to and from overdrive annoyed people driving automatics between 30 and 45 mph - guess I won't get one of those). So I'll take it in when it warms up next year. Thanks for all your suggestions. Quote Link to comment Share on other sites More sharing options...
BlueSoob Posted October 9, 2003 Share Posted October 9, 2003 I purchased a 2003 Forester 5spd and in the first week this happened to me. We named the car Zippy but due to that little A/C button in the middle of the console, the button was renamed the snail button. By hitting this button it makes me feel like I'm back in my 88' GL Wagon again. I have found tis nothing but the compressor kicking off and on - making a 'lurch' in power -esp noticable around town or when accelerating. The only thing i have found when it is cold is that it seems more noticable and I can hear it louder when it kicks on. Resetting the ECU does not help. I've already had a computer failure at 30,000 miles - and having that all reset does not fix the problem. I've experienced the same thing on my 88 GL, my 93 Legacy and even the 03 Forester. If it bothers you that much, roll down the windows for air. It may even help with your gas mileage! Just my 2 cents.:wave: Quote Link to comment Share on other sites More sharing options...
Sweet82 Posted October 9, 2003 Share Posted October 9, 2003 When it's cool I never use the A/C. Only when it's over 95 do I even use the A/C. And I haven't had the car long enough to use the Heater/defroster. So all my experience is Hot weather related.:madder: Like everyone else, I'd bet it's the compressor. It seems the have gone away now the weather is cooler(less A/C use?). Seems to me it was most noticable under 40 but would still be present at freeway speeds. I would call it a hesitation/hickup. Seems like it didn't want to accelearate with out complaining and at a constant throttle it seemed ok. Hummm? Glenn 82 Hatch, 4/60 A/C 01 Forester, real A/C Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted October 9, 2003 Share Posted October 9, 2003 Perhaps the A/C system is overfilled or a sensor is bad? Carl 1 Lucky Texan Quote Link to comment Share on other sites More sharing options...
haru182 Posted October 9, 2003 Share Posted October 9, 2003 WTF......I have the same goddamn thing i can't figure out what it is but the AC lurches at highway speeds. I bought the car in the summer and drove it for the first time on a 300 mile drive back to my house...unforntunently it was 97 degrees out and the AC did that...my first drive in the damn thing. I have never tried to completly disconect the battery but i have lots of electrical problems that seem like they could be alliviated by that....do I just pull the positive or both and how long do i leave disconnected. Thanks for info Quote Link to comment Share on other sites More sharing options...
theotherskip Posted October 9, 2003 Share Posted October 9, 2003 haru - always disconnect the negative first when removing the battery, and in this case, that is all that is necessary. about 45 minutes should do it... if when you remove the positive first, it is easier to accidently short the battery to ground (anything metal on the car). Quote Link to comment Share on other sites More sharing options...
1-3-2-4 Posted June 23, 2010 Share Posted June 23, 2010 I hope I don't get flamed for bumping an old post.. but I've noticed this on my car too 95 Legacy 5spd anyways I don't ever remember it being this bad on an auto but in stop n go traffic crawling at 5 mph it's rather annoying. Quote Link to comment Share on other sites More sharing options...
ericem Posted June 23, 2010 Share Posted June 23, 2010 Same thing with my car too!!!! It's extremely annoying. I might have overfilled the a/c though which would make sense I guess. Quote Link to comment Share on other sites More sharing options...
Timberwolf530 Posted June 23, 2010 Share Posted June 23, 2010 (edited) Well I'm not going to flame you, I'm going to thank you. I just started a post the other day titled "'03 Legacy Idle/OD problem when A/C is on" about the very same thing because I did a search and couldn't find anything. The only thing I forgot to put in was that it doesn't do it before it warms up. At first I thought it was tranny related: old fluid, dirty filter, maybe a stuck valve body. I replaced all 10 qts with synthetic and used Lucas transmission fix, and it didn't help. Hey, at least I have all new fluid though. I'm not convinced it is the compressor kicking & out though because no matter how many times I let up and reapply, it still does it. Unless the compressor is somehow activated by my gas pedal, I don't see how it could be related. My freon was low, but I added 1 can of Subzero and brought it up to 45 lbs, which is within the proper range for the air temp when I measured it. I also don't believe it's normal because not everyone complains about it, and trust me if your car was doing what we are describing, you would complain about it. I have owned a '98 Legacy (MT) & a '99 Outback (AT) and neither of them did it. It won't do it if I leave it in third (no OD), & it won't do it in OD with the air off, but if I combine the two it does it every time after the car warms up. I can understand how the idle issue may be related to cycling, but not the lurch when underway. Edited June 23, 2010 by Timberwolf530 Quote Link to comment Share on other sites More sharing options...
1-3-2-4 Posted June 23, 2010 Share Posted June 23, 2010 Same thing with my car too!!!! It's extremely annoying. I might have overfilled the a/c though which would make sense I guess. and mine is underfilled at the time still the same.. I remember awhile back people said they could feel the A/C compressor kick on and back then I drove an auto (yuck) I was like I don't feel anything.. But now i have a stick and I can tell when it kicks in when driving at 80 Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted June 24, 2010 Share Posted June 24, 2010 Yeah that AC compressor just completely sucks the life out of these things. You wanna know when it really sucks? When you're stuck in traffic for an hour at 11 at night, with 2+ hours of driving left to do to get home, in the rain, just barely moving in first gear. (last sunday, what fun!) Just idling along nice and smooth then bam that compressor kicks off and the car lurches and kicks and throws you around. Then it does it all over again when it comes back on. Try it sometime, I bet you'll love it as much as I did. Quote Link to comment Share on other sites More sharing options...
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