Check engine light was on....now it's off!

Discussion in 'General Motoring' started by Debra Co, Jun 15, 2004.

  1. Debra Co

    Debra Co Guest

    Well, this would be my second go around with the dreaded CEL. Last week it
    went on steady. Stayed on for 4 days. I drove around ignoring it. Pretty
    sure it wasn't the gas cap issue. Yesterday morning, it was no longer on.
    About a year ago, it was on, took it to dealer, they reset the codes, I never
    even found out what the codes meant.

    Since it's off now, am I ok to just pretend this whole incident never happened?
    I'm just out of warranty and don't really feel like paying for a diagnostic
    visit.

    The car is a 2002 OBW LL Bean 6 cyl, 40250 miles. In the past month alone, I
    drove it hard at around 75-80 mph for 3000 miles. Could this have something to
    do with it? Just about due for another oil change now, but didn't get one yet.

    thanks!
     
    Debra Co, Jun 15, 2004
    #1
    1. Advertisements

  2. Debra Co

    Alan Smith Guest

    Has happened to me at least 4 times since the car was new (2001 VDC). First
    two times I took it back to dealer and,both times, he allegedly replaced
    something I think he called a "sender"in the gas tank. Both times, though,
    he said no harm in driving car until he could take care of the fix ... a
    week or two. Last two times I said "nuts" and just continued driving,
    Problem eventually went away. Once, time before last, VDC Off light came on
    at about same time as Engine Light. Within a day that returned to normal
    and within a couple of days (fairly light local driving) engine light went
    off too.

    Frankly, I'm not sure just what the Check Engine Light is allegedly
    checking, but, from my experience at least, it seems eminently disregardable
    AS LONG AS THE CAR SEEMS TO BE RUNNING PROPERLY. If something else is
    happening at the same time (back firing, stalling, excessive exhaust, power
    loss, whatever) get thee to a dealer without hesitation.
     
    Alan Smith, Jun 15, 2004
    #2
    1. Advertisements

  3. Debra Co

    Alan Guest

    In all cars, when the CEL light is on steady, it means that there is some
    sort of problem with the emissions. It is nothing serious, and you can
    continue driving the car. Many times, the condition clears up, and you are
    left with a mystery. Could be water or in the gas, blocked air intake,
    almost anything that would affect the emissions.If the light does not go out
    by the next service, have them take a look.

    If the CEL is fLaShInG, that is usually serious, and you should take the car
    to the dealer immediately.
     
    Alan, Jun 15, 2004
    #3
  4. Debra Co

    Mickey Guest

    I wouldn't write off the gas cap just yet. Several months back I
    had a problem with CEL coming on the going off numerous times for
    almost a month. Finally took the cap off, cleaned off the filler neck
    real good to insure it was real smooth, next removed the rubber seal
    on the cap and cleaned it well. CEL hasn't been on since that time.

    Mickey
     
    Mickey, Jun 15, 2004
    #4
  5. Debra Co

    Sam Li Guest

    Well, I would first find some place that would read the code for free, like
    autozone, or 76 gas stations since there's no autozone near me, to read the
    error code. If your CEL is on, there can be an error code stored in your
    Engine Control Unit computer, and reading it can let you know what the ECU
    "think" the problem is. If the light goes off then there's no code stored.

    And yes a computer can always be fooled. There was once my CEL was on and
    the error code told me there was leak in a pipe, I found no leak and reset
    it. It never bothered me again.

    Sam
     
    Sam Li, Jun 15, 2004
    #5
  6. Debra Co

    name Guest

    What makes this out of warranty?
     
    name, Jun 15, 2004
    #6
  7. 3Yr/36K all inclusive.

    Engine and Powertrain mechanical
    5Yr/60K miles, you pay for computer diagnostics.
     
    Skweezieweezie, Jun 16, 2004
    #7
  8. Debra Co

    anon Guest

    Just read this thread - my apologies if I am not replying in the correct
    manner....

    But can somebody please explain the fuel cap / CEL relationship for me?
    I've never heard of this before. Is there sensors/wires in the filler
    neck that register emissions???

    Thanx in Advance
    spinifex
     
    anon, Jun 17, 2004
    #8
  9. Debra Co

    anon Guest

    Just read this thread - my apologies if I am not replying in the correct
    manner....

    But can somebody please explain the fuel cap / CEL relationship for me?
    I've never heard of this before. Is there sensors/wires in the filler
    neck that register emissions???

    Thanx in Advance
    spinifex
     
    anon, Jun 17, 2004
    #9
  10. Debra Co

    CompUser Guest


    It's not exclusive to Subies anymore...in the
    quest to reduce emissions, raw fumes from
    evaporating gasoline are also considered
    pollution. I haven't done the "complete"
    analysis, but I'd guess there's an "air" line to
    the intake from the fuel tanks, that will put a
    slight vacuum in the tank headspace, to pull
    fumes into engine. There's a charcoal canister
    back there too, that absorbs fumes during periods
    of nonoperation, and should be in the draw-down
    loop, too.

    All that puts a slight vacuum on the tank
    headspace, which includes the filler neck. If
    the gas cap is loose, the vacuum won't develop.
    A vac sensor in that area will notify ecu if the
    proper vacuum level is not achieved, and the ecu
    will store the corresponding error code, and
    flash that darn lil light.

    Steve
     
    CompUser, Jun 17, 2004
    #10
  11. Debra Co

    Todd H. Guest

    There's an evaporative pressure sensor in modern fuel tanks to measure
    the vapor pressure in the tank above the fuel.

    Too low a pressure, and your CEL will come on indicating either a gas
    cap seal failure, a hole in the tank, etc.
     
    Todd H., Jun 17, 2004
    #11
  12. Debra Co

    John O Guest

    Too low a pressure, and your CEL will come on indicating either a gas
    I wonder what the cost trade-off is for manufacturers to add a light that
    says "Check fuel system" instead of the CEL??? Or even a special flash
    sequence, or at least something more useful than the "something is wrong
    with this huge piece of equipment, but it's top secret and it'll cost you to
    learn what it is" light. :)

    -John O
     
    John O, Jun 17, 2004
    #12
  13. Debra Co

    Todd H. Guest

    I'm told AutoZone will tell ya for free with their ODBII reader.
     
    Todd H., Jun 17, 2004
    #13
  14. Debra Co

    Mickey Guest

    Many of the codes are common regardless of mfgr. See the same
    description for code number on my Ford CV. This is very confusing
    when some codes mention bank 1 or bank 2. The bank info applies to
    engines with separate systems for left and right banks you might find
    in V6 and V8 engines.

    On my car when the light came on the code was 420 which is a code for
    the cat system, bank 1.

    For all the hundreds of codes, some are not very useful in
    understanding what is actually wrong.

    Mickey
     
    Mickey, Jun 17, 2004
    #14
  15. Debra Co

    Debra Co Guest

    Thanks all for the good replies. The light remains off, and I'm still driving
    around, so keep your fingers crossed!
     
    Debra Co, Jun 18, 2004
    #15
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.