MY Hyundai Veracruz engine (3.8L) idle too low (600 Rpm) in cold weather (less than 40F), when engine is warm and transmission on drive and vehicule stop. This cause a undesirable vibration. When outside tmeperature is more then around 40F it is ok (RPM is 750). When transmission is on Park it is always ok. Any suggestion on cause?

Yes it is high if it still does that when it is warm. Cold idle speed is higher. Perhaps they will slow it down at first service.

Typically, the idle speed will be set at a value in the range of 600 to 800 RPM, but the exact value will depend on the number of engine cylinders and whether the vehicle is equipped with a manual or automatic transmission.

Kia Sportage Engine idle speed is high Inspection Costs

It is a little high but if the ambient temperature is very low it would be ok providing you understand that there will be a bit less economy. You can fine tune the choke to drop another notch on the accelerator cam so that it would idle at say 1500rpm and the gear engagement would be less harsh

You may be correct with what you think the problem may be, but another good thing to check is your coolant level. A low coolant level could cause false readings from you coolant temp sensor, which in turn will cause an engine hunting condition that you described.

Hi Joseph, When starting the vehicle from cold in cold weather, the RPM can be as high as 1300 and in temperate climates about 1100 RPM. The RPM will drop to normal as the coolant is warmed. Normal idle speed is between 750 for Auto and 650 to 700 for manual transmission. Regards John

Its cold start issues:----
Go through the list of help links mentioned below:----

Click the link :----

Cold start problem and vehicle shudder around 2500 to 3500 rpms
http://repairhelpcenter.blogspot.com/2012/10/cold-start-problem-and-vehicle-shudder.html
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Low idle when cold out side?
http://repairhelpcenter.blogspot.com/2011/12/low-idle-when-cold-out-side.html
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Ford explorer 4.0 will not idle when cold?
http://technoanswers.blogspot.in/2012/02/ford-explorer-40-will-not-idle-when.html
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Automatic transmission shift lever hard to move on cold mornings?
http://technoanswers.blogspot.com/2012/01/automatic-transmission-shift-lever-hard.html
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Car won't start when cold?
http://schematicsdiagram.blogspot.com/2011/12/car-wont-start-when-cold.html
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It can be issue with IAC( idle air control valve) causing the problem.

There are many other possibilities causing these idle issues. Engine idles rough.

There are few help links with solutions to troubleshoot such idle issues.

I suggest you refer the link below and follow its troubleshooting details:------

Click the link below:-----

Ford Expedition IAC valve replacing

http://technoanswers.blogspot.com/2012/12/ford-expedition-iac-valve-replacing.html

Bad miss at idle?

http://technoanswers.blogspot.com/2012/01/bad-miss-at-idle.html

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Stumbling and stalling at idle after engine rebuild?

http://schematicsdiagram.blogspot.in/2012/03/stumbling-and-stalling-at-idle-after.html

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1999 Ford F-150 Idles rough and quits when gas pedal is pressed less?

http://technoanswers.blogspot.in/2012/01/1999-ford-f-150-idles-rough-and-quits.html

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Engine stumbles coming off idle when warm?

http://repairhelpcenter.blogspot.com/2012/01/engine-stumbles-coming-off-idle-when.html

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Erratic idle on car?

http://schematicsdiagram.blogspot.com/2011/12/erratic-idle-on-car.html

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Cold start problem and vehicle shudder around 2500 to 3500 rpms

http://repairhelpcenter.blogspot.com/2012/10/cold-start-problem-and-vehicle-shudder.html

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Low idle when cold out side?

http://repairhelpcenter.blogspot.com/2011/12/low-idle-when-cold-out-side.html

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GMC Sonoma Stalls and idles low

http://technoanswers.blogspot.com/2012/10/gmc-sonoma-stalls-and-idles-low.html

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GMC Idle Air Control (IAC) Valve Replacing?

http://schematicsdiagram.blogspot.com/2011/12/gmc-idle-air-control-iac-valve.html

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1996 Camry intermittent engine failure while idle?

http://repairhelpcenter.blogspot.com/2011/10/1996-camry-intermittent-engine-failure.html

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Engine quits at idle?

http://repairhelpcenter.blogspot.com/2011/10/engine-quits-at-idle.html

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Car overheats and Air blows hot at idle?

http://howtobyme.blogspot.com/2011/11/car-overheats-and-air-blows-hot-at-idle.html

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High Idle Problem

http://repairhelpcenter.blogspot.com/2012/10/high-idle-problem.html

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While stop engine idles like cylinder missing?

http://schematicsdiagram.blogspot.com/2012/01/while-stop-engine-idles-like-cylinder.html

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Idle flair is noticed on car? Rough idle? car will not idle? Erratic idle speed?

http://technoanswers.blogspot.in/2012/02/idle-flair-is-noticed-on-car-rough-idle.html

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High rpm in neutral? Inconsistant high RPM in neutral?

http://technoanswers.blogspot.in/2012/02/high-rpm-in-neutral-inconsistant-high.html

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Vehicle stumbling at idle and shows code 54?

http://schematicsdiagram.blogspot.in/2012/03/vehicle-stumbling-at-idle-and-shows.html

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Rough idle, staling and Erratic shifting?

http://technoanswers.blogspot.in/2012/03/rough-idlestaling-and-erratic-shifting.html

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While stop engine idles like cylinder missing?

http://schematicsdiagram.blogspot.com/2012/01/while-stop-engine-idles-like-cylinder.html

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These details will help.

Thanks.

Its cold start issues:----

Go through the list of help links mentioned below:----

Click the link :----

Cold start problem and vehicle shudder around 2500 to 3500 rpms

http://repairhelpcenter.blogspot.com/2012/10/cold-start-problem-and-vehicle-shudder.html

----------

Low idle when cold out side?

http://repairhelpcenter.blogspot.com/2011/12/low-idle-when-cold-out-side.html

--------------

Ford explorer 4.0 will not idle when cold?

http://technoanswers.blogspot.in/2012/02/ford-explorer-40-will-not-idle-when.html

--------

Automatic transmission shift lever hard to move on cold mornings?

http://technoanswers.blogspot.com/2012/01/automatic-transmission-shift-lever-hard.html

----------

Car won't start when cold?

http://schematicsdiagram.blogspot.com/2011/12/car-wont-start-when-cold.html

-----------

These will help.

Thanks.

It's been almost 2 years since you posted the question so it's likely you will not see my answer to your question.

First, do NOT make any adjustments to your throttle body idle setting. The screw most likely never budged since 2006 so you should not touch it since this is not the root cause. But yes it is wise to check all vacuum lines as "craig" suggested.

I have a 2007 Corolla CE, 1.8 liter VVT engine, 5 speed manual transmission which I bought new from the dealer. Currently has about 108k miles on it. After about 4 or 5 years in cool to cold weather it started doing the same thing. I researched it online then asked my local Advance Auto Parts person who confirmed my hunch. It is known as "idle hunting" when the engine is cold, in colder outside temperatures the idle rpm's will increase up to roughly 2000 rpm then drop to idle, then back to 2000 rpm, then repeats multiple times. Then after driving a short distance, stopping and running at idle, the idle speed may drop to 600 or 500 or as low as 400 rpm, running quite roughly but still keeps running. My Corolla normally idles smoothly and steadily at 800 rpm when warm or hot. The idle hunting or low idle rpm will typically correct itself when the engine warms up enough.

The problem: the intake manifold gasket has aged and shrunk a bit, allowing engine compartment air to get pulled directly past the gasket and into the cylinder head intake port. This causes an imbalance between the reduced air filter airflow sensed by the Mass AirFlow (MAF) sensor versus the actual air/fuel ratio versus the engine rpm versus the oxygen level in the exhaust stream. The gasket will shrink more as the temperature under the hood drops, allowing more air to flow past the gasket. The Engine Control Unit (ECU) is simply trying to do its job as programmed by increasing fuel delivery to compensate for the overall imbalance, then when rpm's get too high it will reduce fuel delivery.

The solution: purchase a new intake manifold gasket for roughly $10 to replace the stock gasket. Mine is a thin orange polymer gasket with round cross-section which seals around all 4 intake ports. You can search for instructional video of how to install it on YouTube.

I purchased one but did not install it yet. I am sure this will resolve the problem since all other suggested fixes I found on the internet did nothing but unnecessarily frustrate the owners.

READ THIS (happy ending so far...):
audi a4 2L turbo quattro, manual transmission with 98,000 KM. Perfect conditions, no oil leaks whatsoever.

Left the car off for two weeks in very cold weather (-10C down to -25C). When I restarted, it started immediately but with heavy rattling noise due to camshaft adjuster not getting enough oil pressure. After 3 minutes of warming up (outside temp.: -12C) at very low rpm (below 2,000rpm), I start moving the car. Still hearing heavy rattle noise. As soon as I pass 2,000 rpm, I get a scary red warning, low oil pressure. Turn off the engine immediately. In 1 minute, I re-start the car and the engine lights check ok, so I drive in first gear super slow (1,200rpm) hearing the same rattling noise. After another minute, finally the noise all the sudden disappears and the car starts running just fine.

Called Audi dealer and they told me that in extreme weather conditions, I should warm the engine for 10-15 minutes if necessary before start moving.
Take away: luckily, I didn't screw up the engine since I was using it at extremely low rpm (easy to do with clutch and manual transmission) until the oil reached full pressure. I am pretty sure now that the problem was leaving the car off for such a long time in freezing weather. All the oil flows back to the bottom, and when I restarted it, the cold oil with high viscosity took a long time to reach all the parts of the engine, specially the camshaft adjusters that are actuated by using oil pressure. Next day, the car started at -9C perfectly without making any noise (as usual). Basically, the longer you leave your audi in cold weather, the longer you might hear the rattling noise until the oil reach full pressure inside the engine. My car took 6 minutes to fix it after couple of weeks in cold weather. This makes sense to me; in fact, in the past I only heard the rattling noise after leaving the car off for a couple of days in the winter.
So far, this has had an happy ending....

ur cold start needs adjustment then when the engine is warm it should idle at 600 to 650 rpm

OK, folks, here's the scoop. The dealer took our Veracruz in for diagnostic testing and determined the cause of the problem was the actuator for the Electronic Transmission Control system (ETC).

Apparently, in later model cars like the Veracruz, a computer controls the transmission as well as the engine for optimum performance.

If the computer detects a severe enough fault in one of the components of the ETC (e.g. bad sensor, bad component, etc), it places the vehicle in limp home mode.

Based on my experiences, when in limp home mode, the transmission is forced to stay in 3rd gear, the engine will not exceed 2000RPM, the accelerator is not responsive past 2000RPM, and the engine runs rough (probably because the mixture is changed to very rich). The philosophy here, as was explained to me by somebody who works for Hyundai, is to allow the vehicle to continue operating long enough so that it can be driven to a safe location or for service.

I asked whether or not this limp home "feature" could be disabled at the dealership, but apparently it cannot.

I have alerted some folks at Hyundai Motor USA to this thread so they can do further research if the problem begins to affect more individuals than just us three.

FYI - I am in no way shape or form a mechanic or mechanically-minded, so if I have explained anything correctly, I will gladly accept further corrections/explanations from an expert or mechanic. :)