Warming up the engine....

Discussion in 'General Motoring' started by Pravin Nair, Nov 3, 2003.

  1. Pravin Nair

    Pravin Nair Guest

    Hi there,

    How important is it to warm up your engine first thing in the morning?.

    Does it increase the life time of the engine or some such?.

    Just curious.

    Pravin Nair.
    Pravin Nair, Nov 3, 2003
  2. Pravin Nair

    Robert Guest

    I run it for 30 sec or so, then drive slow for the first couple of miles
    (until I get to the freeway)
    Robert, Nov 3, 2003
  3. Pravin Nair

    Jafir Elkurd Guest

    It is best to let the car idle for a few seconds to make sure everything is
    lubricated, and then just take it easy until the car warms up completely.
    No reason to just sit there and waste gas while it warms up. Also it is
    possible that the extreme rich running condition of a cold engine could
    cause cylinder lubrication problems, so you'd be better off driving the car
    so that it will warm up quicker.
    Jafir Elkurd, Nov 3, 2003
  4. Pravin Nair

    eraser Guest

    by letting it idle to warm up you actually cut your engine's life. Start it,
    count to 10, then drive. Be very easy on the car (eg NO speeds over 45 mph).
    as soon as your coolant temp gauge raises to its middle point (or close to
    it), drive it as you would drive it normally with no ;-))) caution.

    eraser, Nov 4, 2003
  5. Pravin Nair

    Patrick Guest

    Not to mention you will have to replace your muffler and pipe every 2
    years if you spend too much time warming up. All the moisture
    collected inside by condensation while the car sitting warming up in
    cold weather will cause them to rust from the inside.
    Patrick, Nov 4, 2003
  6. It's not good for modern cars. They less time they're idling cold, the
    better. That's when they're running dirty, having poor fit between
    moving parts, collecting combustion contaminates in the oil, and not
    getting good oil circulation.

    Give the engine enough time to stabilize, about 3 to 20 seconds, then
    drive it gently. Avoid cold RPMs near redline because the oil may be
    too thick to spread over the metal surfaces at that speed. Of course
    it's best to not drive your car into a ditch because the windshield is
    frosted over, but don't idle it warm without a need.

    Check your manual for details.
    Kevin McMurtrie, Nov 4, 2003
  7. Pravin Nair

    NetSock Guest

    I have to disagree with just about every response.

    First, some credentials...I was a 12 year certified technician, and
    regularly did engine rebuilds on both gas and diesel engines. As a fleet
    manager, will also did extensive wear studies and regular in-depth oil
    analysis. While I am no longer "in the field" I still get my hands dirty
    building hi-performance engines for boats as a hobby.

    With that said...I will make this blanket statement...

    "Allowing the engine coolant to reach its maximum operating temperature at
    idle after a cold start, will extend the life of the engine."

    Think about it...20 degree block, and your going to drive away after 30
    seconds!? Tolerances are too tight in a cold engine for loading
    purposes...you are "shaving" longevity away from your engine. We have done
    those precise studies in our fleet, and that is our findings. My very own
    '94 Accord with 138k miles on it, has *always* been completely warmed up,
    and to this day, runs like its brand new.

    Talk about rusting your exhaust system by letting your car warm up, is
    nonsense as well. That doesn't even make sense.

    I welcome any debate on the subject, and I sure there is good rational for
    those who disagree, but we actually did the studies, and tore down the
    engines afterwards. Believe me...seeing, is believing. ;)

    Take care.
    NetSock, Nov 4, 2003
  8. Pravin Nair

    NetSock Guest


    Modern engines that are properly tuned do not run "rich" when cold. They may
    be running "richer" than normal conditions, but not overly so.

    Today's modern engines are designed to burn ALL the full at any given
    temperature range. If your modern engine is having fuel wash at ANY time,
    there is something wrong.

    Take care.
    NetSock, Nov 4, 2003
  9. Netsock,

    Have you done any testing with regard to systems like the PreLuber?

    It'd be interesting to compare an engine on PreLuber and an engine that
    simply warms up to operating temperature.
    Elmo P. Shagnasty, Nov 5, 2003
  10. Oh, yeah, btw:


    Elmo P. Shagnasty, Nov 5, 2003
  11. Pravin Nair

    dizzy Guest

    You're cracked. How long would that take? 10 minutes? It's a
    machine. Drive it.
    dizzy, Nov 5, 2003
  12. Pravin Nair

    Jafir Elkurd Guest

    So you are saying that a car that is overnight cold in the middle of winter
    would have the exact same emissions percentages of a car that is fully
    warmed up? That's just not true.
    Jafir Elkurd, Nov 5, 2003
  13. Pravin Nair

    NetSock Guest

    No...thats not what I said.

    '03 S2000
    '94 Accord

    It's just about going fast...that's all...

    NetSock, Nov 5, 2003
  14. Pravin Nair

    NetSock Guest

    Very good question!

    We did do some analyst on boats, and found it to make quite a difference on

    "Dry run" is when your engine is turning, but oil pressure has not
    stabilized. This *IS* the worst time for any piston engine. It, of course is
    worse in cold weather, but we found the biggest engine killer to be...get
    this...over servicing.

    Ever notice that you oil light stays on an extra 3 to 6 seconds after you
    change your oil? Well, that is "dry run". The engine is running, and you
    have none to low oil pressure...not a good thing.

    So if you were to change your oil every 2k...think about it...after 40k, you
    would have over 1 to 2 minutes of running your engine with no oil pressure!

    Filling your filter before installation can help, but not all filters are
    mounted vertically.

    Oil companies and engine manufacturers want you to change your oil every 3k.
    Our oil analysis showed that we were throwing away a *LOT* of good oil on an
    average commuter engine. We found that 4500-5000 miles was better serving
    point in that environment.

    Don't get me wrong...there ARE applications to change every 3 k, but the
    average passenger car doesn't need it that often.

    Back to the pre-luber...a GREAT idea...works as it should...we get a full
    extra summer season out of our 425hp 460 cid jetboat, however, I cant
    recommend it for low load (average commuter) car...its just not worth the
    cost. Simply by changing drivers habits and servicing, its easy to get 200k
    out of an engine nowadays. By that time, other aspects of the car are in
    issue, but with a work horse (truck, towing, boat, hauling, hi-performance)
    I would HIGHLY recommend it.

    Take care.

    '03 S2000
    '94 Accord

    It's just about going fast...that's all...

    NetSock, Nov 5, 2003
  15. Pravin Nair

    NetSock Guest

    Tom and Ray (to whom I've never heard of) seem to be good ol' boys and well
    intentioned, but I didn't catch their credentials. Nor did they give any
    real explanation to their methods.

    Like I said, to each there own...but Ill stick with real world facts to make
    my judgments.

    Take care.

    '03 S2000
    '94 Accord

    It's just about going fast...that's all...

    NetSock, Nov 5, 2003
  16. Pravin Nair

    NetSock Guest

    Only on Saturday nights. :)
    It depends.
    My Accord gets into the "operating" range after about 4 minutes @ 32 F.
    You can drive it, or drive it into the ground...which ever you prefer. :)

    Take care.

    '03 S2000
    '94 Accord

    It's just about going fast...that's all...

    NetSock, Nov 5, 2003
  17. Pravin Nair

    Jafir Elkurd Guest

    If it burning ALL the fuel at any point, the emissions would be the same at
    any point. Heck, cars wouldn't even need a catalyst if they could do what
    you are saying.
    Jafir Elkurd, Nov 5, 2003
  18. Pravin Nair

    NetSock Guest

    No they wouldn't. RPMs are a HUGE factor.
    Catalyst are designed to deal with the nitrous by products from burning fuel
    (gasoline). The catalytic converter has little to do with unburnt fuel.

    I will however clarify...modern engines are designed to burn 97% of the fuel
    at any temperature. The remaining 3% could never result in "washing" of the
    cylinders...which was my point.
    NetSock, Nov 5, 2003
  19. So how long does it take for one of those diesel engines to warm up
    at idle in cold weather?
    Big deal. Lots of people have cars with more mileage and no problems
    without doing any idle warm-up.
    Timothy J. Lee, Nov 5, 2003
  20. Big deal. Lots of people have cars with more mileage and no problems
    without doing any idle warm-up.[/QUOTE]

    In fact, my 120K mile 92 Civic, with 3K mile oil change intervals and
    minimal warmup times, showed an oil analysis where the engine was in
    brand-new shape. And it continues to run.
    Elmo P. Shagnasty, Nov 5, 2003
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