High RPM on cold start!

Discussion in 'General Motoring' started by Vineeth, Dec 28, 2006.

  1. Vineeth

    Vineeth Guest

    I seem to recall a previous post about a similar problem earlier but I
    can't seem to find it. I have of late noticed that as soon as I start
    the car (2006 Sonata V6) in the morning it revs up to 2k rpm then
    settles down to around 1200 for a while. Doesn't go below 1000 for a
    long time. Rarely get time to wait & see if it will ;)..
    Which brings up another question, I recently read on a brochure in a
    car dealers shop that there is no need to idle the car to warm it up
    before driving away as this doesn't improve fuel consumption, but only
    consumes extra fuel. However I have always thought it is best for the
    engine to warm up a bit before driving away...
    thanks for any inputs...
    Vineeth, Dec 28, 2006
  2. This has been a controversial issue for some time. Near as I can tell,
    thee really is not need for a warm up time, however, the first couple of
    miles should be at a modest speed. This is not just for the engine, but for
    warming of the differential, wheel bearings, transmission, etc.

    Lubricants used in the past 10 years are far superior to anything used in
    the 1930's when many of our driving customs started. Cold carburetors did
    not always function as well with the automatic choke like the present fuel
    injection either. Nor do we have to remember when to push in the choke knob
    on the dash.

    I have a remote starter so the car will be warmed up in many cases.
    Edwin Pawlowski, Dec 28, 2006
  3. The brochure was right, warming up a car does nothing but waste fuel and
    pollute the air. The best way to warm up a car is to drive it.
    Brian Nystrom, Dec 28, 2006
  4. Vineeth

    Matt Whiting Guest

    Mine I-4 doesn't rev that high, maybe 1600-1800 and then settles down to
    1000 until warmed up. Yes, idling more than a few seconds is just
    wasting gas. I idle maybe 10 seconds and then drive away slowly.

    Matt Whiting, Dec 28, 2006
  5. Vineeth

    hyundaitech Guest

    2000 RPM doesn't sound abnormally high for a cold start in cold weather.
    Part of the strategy is to warm the engine quickly enough to be able to
    use the oxygen sensors to be able to control fuel mixture.
    hyundaitech, Dec 28, 2006
  6. Vineeth

    Vineeth Guest

    Thanks a lot. Now I can rest assured that my car is not peculiar.. & I
    need not feel guilty for not idling too long..
    I must say this is an awesome group...
    Vineeth, Dec 29, 2006
  7. Vineeth

    Mike Marlow Guest

    I disagree - to a point. I have experienced way too many sub-zero mornings
    where the lubricants in the car are thickened up, for me to jump right on
    this practice. Try this - leave your car outside overnight on a sub-zero
    night. Jump in, start it up and put it in gear, and take off. Notice if
    there is any difference at all in it's response versus the response once
    things have warmed up a bit. Not to mention, that in the winter time it is
    more than a little important to have such things as defrosters functional
    when heading down the road. That does not happen with a cold engine.
    Mike Marlow, Dec 29, 2006
  8. Vineeth

    Bob Guest

    Lots of subzero mornings would be a good reason to use synthetic oil - at
    least during the winter. I'd bet that it would actually make a difference in
    the life expectancy of the engine under these - lube oil available, and
    circulating, vs. lube oil in jello form in oil pan - conditions.
    Bob, Dec 29, 2006
  9. Vineeth

    Matt Whiting Guest

    This is the only reason I use synthetic. Even though winters have been
    warmer the last couple of decades, we still get several subzero days
    each winter typically and -20 happens every 3-4 winters or so.

    Although, I must admit that the new 5W20 dino oils flow pretty well in
    the cold. I ran the OEM oil in my Sonata for most of last winter as I
    bought the car right before Christmas. It cranked well even at 10 F.
    We didn't have any below zero days last winter as I recall. And when I
    switched to Synthetic 5W20 the difference as compared to the dino oil
    was much less dramatic that in days gone by with 10W30 and heavier oils
    so I suspect that even with dino oil you are fine down to zero or below
    if you use the recommended 5W20 weight.

    Matt Whiting, Dec 29, 2006
  10. Vineeth

    Mike Marlow Guest

    That might be the instinctive conclusion Bob, but dino has served well over
    the decades. I've never lost a car to lubrication problems, even with the
    thickening issues. It's not all about the lubricants though. It's also
    about the metal components that make up such things as engines,
    transmissions, etc. They are built with tolerances, expansions, etc. There
    is an operating temperature for a vehicle and it's not dead cold.

    And... as I had stated earlier, you need a warm engine to get functional
    defrosters, etc.
    Mike Marlow, Dec 30, 2006
  11. Vineeth

    Mike Marlow Guest

    I've been quite satisfied, as you observe Matt, with the flow of 5W20 or 30
    in the winter. As noted in my other response, though, it's not all about
    the oil. The engine has to come up to temp for many things to be right -
    tolerances, mixture controls, etc.
    Mike Marlow, Dec 30, 2006
  12. Vineeth

    Double Tap Guest

    With all due respect the question of warming up the engine or not to an
    operating temperature that will give you defroster capability does not
    address the major issue.

    In sub zero temps or those below 20F you face the issue of Automatic
    transmission function and even more importantly suspension movement.

    You can have the engine sit for a full 5 minutes at idle and if you drive
    off and hit a moderately deep pot hole at sub zero temps you have a MUCH
    greater chance of doing damage.

    I have been advised by a number of factory techs that warming up the engine
    for 30 seconds to one minute is all that is necessary, however one must be
    careful not to stress the trans and suspension until the car has had some
    miles put on to warm these components up.

    Severe cold is the best friend the repair shops have. It does far more
    damage to parts other that the engine.
    Double Tap, Dec 30, 2006
  13. Vineeth

    Matt Whiting Guest

    That isn't much of an issue with today's engines. Most have aluminum
    blocks which match the aluminum pistons much better from a coefficient
    of thermal expansion perspective. Driving away slowly and keeping the
    revs down for the first mile or two is the best way to warm things up.
    I've done this for 20 years now with very good results. Usually by the
    time I get done scrapping the windshield, the car has idled at least 1
    minute and often longer which is plenty as long as you can see out the
    windshield. The Sonata is worse in the defrost department than my other
    vehicles so often the fog on the windshield is the limiting factor for
    me time-wise.

    Matt Whiting, Dec 30, 2006
  14. That is what I've done in the past. Yes, it works well. The two miles to
    the highway is sufficient to get it ready for some speed. It does take some
    time for the oil to really get heated though.

    My Sonata new has a remote start. I do not intend of driving off on a cold
    car nearly as often. Now that the weather is getting cold, I set the system
    to "defrost" when I park it for the night and by the time I leave the house,
    the windshield is clear. Only 3 months old, I've not had a serious need for
    defrost yet so I'm not sure how it compares to other cars.

    Sure is nice to hit that button and go out to a reasonably warm car,
    including the heated seat. I don't know why I never put a remote in my last
    couple of cars. Any I own in the future will have it.
    Edwin Pawlowski, Dec 30, 2006
  15. Vineeth

    Matt Whiting Guest

    I agree that is why I have a two-car heated (sort of heated anyway)
    garage. The only problem is I now have three cars. Since the Sonata is
    the newest and cheapest car, it sits outside. I keep my Chevy truck
    with snowplow inside as when I need to plow my driveway I don't want to
    have to worry about my plow vehicle starting or having to clear all the
    snow off so I can see to plow. It is nice to open the garage door,
    lower the plow and away I go!

    Matt Whiting, Dec 30, 2006
  16. Garage? Oh, the place I have my workshop. Both cars sit outside
    Edwin Pawlowski, Dec 30, 2006
  17. Vineeth

    Matt Whiting Guest

    I built a 12x24 outbuilding for shop and lawn equipment, but not being
    heated is a pain in the winter.

    Matt Whiting, Dec 30, 2006
  18. Vineeth

    Double Tap Guest


    A heated garage is great if you live in an area that does not salt the
    You are MUCH better off keeping the car cold if you do not have the ability
    wash off the underside with all the salt accumulation before putting it in a
    area. The warm air will greatly enhance the speed of the salt to work
    corrosive magic
    on the vehicle.
    Double Tap
    Double Tap, Dec 30, 2006
  19. Vineeth

    Matt Whiting Guest

    I agree, but my garage is under my house as part of the basement so it
    gets some heat from the house, hence my comment about "being sort of

    Matt Whiting, Dec 30, 2006
  20. Vineeth

    Mike Marlow Guest

    I leave my plow truck outside so that both cars can stay in the garage.
    Ugh!!! Few things are more fun than cleaning a full size pickup off after a
    couple feet of snowfall. I have a high-rise cap on mine and man can that
    thing hold a pile up of snow.
    Mike Marlow, Dec 31, 2006
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