odorless fumes from the AC vent

Discussion in 'General Motoring' started by jaykay, Sep 18, 2006.

  1. jaykay

    jaykay Guest


    After running the AC for a couple of minutes, I get odorless fumes from
    the AC vent of the car. It does not condense in my hand when I place my
    hand in front of the vents.

    Is it just moisture? Or AC refrigerant that leaks into air stream?

    It was raining and I'm at Chicago suburbs.

    My car is 1996 civic LX (125,000 Mi).

    Thanks in advance.
    Jay K
    jaykay, Sep 18, 2006
  2. jaykay

    Seth Guest

    Sounds like condensation from the AC during a high humidity spell. If it
    continues and is a refrigerant leak you will notice a degradation in your
    ACs ability to "generate cool". If your AC continues to operate normally,
    then obviously you're not losing refrigerant.
    Seth, Sep 18, 2006
  3. Second that. It is not unusual for fog to come out of the vents when
    the humidity is high.
    Gordon McGrew, Sep 18, 2006
  4. Especially if your A/C is working at top efficiency<g>
    Unquestionably Confused, Sep 18, 2006
  5. jaykay

    nm5k Guest

    You may be a wee tad low on refrigerant. Normally, you shouldn't
    see much fog, even with high humidity. Why? with the proper
    charge, usually the coil temp is high enough to avoid blowing fog.
    In most cases, blowing fog is due to being slightly low on charge.
    This causes the coil temp to drop below freezing, and hence, you
    see fog. If charged back up, the coil temp rises above freezing, and
    no more fog. Better cooling too...
    nm5k, Sep 18, 2006
  6. I concur with the other replies. Moisture did not condense on your
    hand, because your hand is warmer than the air from the vent.

    Elliot Richmond
    Itinerant astronomy teacher
    Elliot Richmond, Sep 18, 2006
  7. jaykay

    Woody Guest

    As well as checking refrigerant level check the drain tube isn't plugged.
    Woody, Sep 18, 2006
  8. jaykay

    mpwilliams Guest

    Absolutely normal in humid climes ... turn the A/C controls to Recirculate
    and the 'problem' will almost instantaneously disappear.
    mpwilliams, Sep 19, 2006
  9. jaykay

    jaykay Guest


    It must be because of high humidity. There were no fumes once the
    weather changed!!!

    Thank you all for your replies!!

    Jay K
    jaykay, Sep 21, 2006
  10. jaykay

    nm5k Guest

    It still may be a bit low though. It's quite possible to be low,
    and not fog in some conditions. Myself, I don't really agree
    that it's normal. I live in humid Houston, and mine never does
    that. None of our cars do.
    If you blow fog, that means your evap coil temp is at or
    below freezing. Usually, on a slightly low system, this would
    occur at idle mostly. The pressure may drop below the freezing
    level, but can rise back up when driving due to the higher rpms.
    But... You don't have to rely on my jibber jabber.
    The best way to check that is just look at the sight glass
    if yours has one. Most that have glasses will be canister looking
    things near the front end usually, and will have a little clear sight
    on top. Let the a/c crank up full blast and get stable for a while. The
    glass should be clear. If you see bubbles flowing across the glass,
    it probably needs a shot. If there is no sight glass, you kinda
    have to go by ear.. Myself, I look at the receiver, etc, and charge
    until it has a uniform sweatback. But I also use gauges. The
    sight glass is the best way to check with no gauges. Actually,
    I'll take it's word over the pressures I see.. But almost always the
    pressures will be normal is the glass is clear.
    I had to fix the a/c on the accord I just bought. But it was only a
    leaking service valve, and a cap with no O-ring. Pulled a vacuum,
    charged it, and about 6 weeks later, it's still working good. :)
    Doesn't seem to be leaking at all. Or if it is, it's really small..
    Got really lucky. I was expecting it to leak out in a week..
    And yep, mine never blows fog, and I do have a clear sight glass.
    Between me, and the guy I work with, we still have about 90 lb's
    of freon 12.. :) I just bought another 30 lb jug of 12 the other day..
    The price was right, and I couldn't pass it up. Gotta nuff freon to
    keep it pumped up for a good while.. I kept the system using 12, cuz
    it cools better than retrofiting it to 134a..
    nm5k, Sep 21, 2006
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