High RPM on cold start!

Hi
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...

 

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.

 

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.

 

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

 

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.

 

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...

 

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.

 

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.

 

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

 

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.

 

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.

 

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.

 

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

 

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.

 

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

 

Garage? Oh, the place I have my workshop. Both cars sit outside

 

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

Matt

 

Snip

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

 

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
heated."


Matt

 

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.