My engine is idling too high

it sounds like you have a vacuum leak or the throttle bore needs to be serviced but to be sure this guide can help us fix it.

https://www.2carpros.com/articles/engine-idles-too-high

Please run down this guide and report back.

I'm going down the road and all of a sudden the engine revs up without me pressing the gas petal and it stays like that. i pulled over and shut the car off. waited a few minutes and cranked it again and same problem.

I attached a guide for you of high idle issues.

https://www.2carpros.com/articles/engine-idles-too-high

Your throttle body may be dirty staying open when it should be closed. I attached the procedure for cleaning the throttle body of all carbon deposits.

https://www.2carpros.com/articles/how-a-throttle-body-works

https://www.2carpros.com/articles/throttle-actuator-service

The other possibility is a vacuum leak from a hose that may be loose or broken. I attached a guide for you as well.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Roy

Hi, here is the problem, every time I start the car the engine races, when I put it in drive and take my foot off of the brake it reaches 46 mph with driving three blocks without touching gas pedal.

High idle speed is typical of a vacuum leak. Start with a visual inspection of the vacuum hoses. You can also pinch off various hoses to see if you can find one that brings the idle speed down. If you find that, follow it to its branches and pinch each one to work your way to the leak. You can also run water over the hoses and gaskets while the engine is running and still cold to see if it gets sucked in someplace.

2000 Dodge Neon 4 cyl Automatic

i have a 2000 dodge neon. Car ran fine then suddenly started shaking when approaching any type of stops. Battery terminals where iffy so I changed them. Car ran great for 2 days then started to stall once put in drive. When car is running in park it idles high then low then high then low, put in drive it stalls itself out. Runs fine in reverse though.

Erratic idle speed suggests a vacuum leak. The most common cause would be a disconnected or cracked hose. Many of them are hard black plastic, about half the diameter of a pencil. Certain gaskets can also cause a vacuum leak. If the leak is bad enough, you might also notice that you have to push harder than normal on the brake pedal. Power brakes use engine vacuum for the power assist, so low vacuum means less power assist to the brakes.

Listen under the hood for a hissing sound while the engine is running. You can also use a spray bottle to spray water over the hoses and gaskets while the running engine is still cold. If the idle speed slows down or changes, or you see the water getting sucked in, you've found the leak.

A defective MAP sensor can also cause the symptom you describe, but once the readings go outside of preset limits, it will be detected by the engine computer, and it will turn on the "Check Engine" light. At that point there will be a diagnostic fault code memorized in the computer. Do not disconnect the battery at that point until the code(s) have been read or that valuable information will be lost.

You can also make the computer display the diagnostic codes yourself to see if there are any stored. Only codes that affect tail pipe emissions will cause the Check Engine light to turn on. There are a lot of other codes that will direct your mechanic to the circuit with the problem, but won't cause the light to be on.

caradiodoc

i have a 2000 dodge neon se, it idles itself really really high,really fast while going down the road,and when I come to a complete stop, it finally idles itself down, but then will rev up and down.

Major vacuum leak. Try pinching off various hoses to see which one brings the speed down. You can also use a scanner that displays live data to see what "step" the Engine Computer has set the automatic idle speed (AIS) motor to. Step 32 is typical for normal idle. If it is real low, the computer is trying to lower idle speed without success. If it is real high, the computer is erroneously trying to raise it.

Many scanners also allow you to run the idle speed up to 2000 rpm in 200 rpm increments to see if the AIS motor is working properly.

My car is having transmission problems. When I put it in reverse it just revs up when I press the gas. All of the other gears it drives forward including neutral. I am thinking it is something to do with the shift linkage. But I do not have much experience with Dodge cars. I have had all GM before this. Any help at all would be very appreciated. Thanks in advance!

check for a broken or bent cable. if it shifts the lever to reverse which it sounds like then check fluid level if you can. This guide can help as well.

It sounds like you have a vacuum leak or the throttle bore needs to be serviced but to be sure this guide can help us fix it.

https://www.2carpros.com/articles/engine-idles-too-high

Please run down this guide and report back.

Fluid is good. In park it moves forward. In reverse it does nothing. Drive, neutral, 1, and 2 it moves forward. Cable is good. I pulled the cable off the linkage on the tranny and moved that manually with a friend in the car to use the brake and the same things happened.

it's probably a trans that needs overhaul then if no check engine light is on then that is the problem

I've heard a lot about a solenoid going bad. What happens exactly when those go out?

a solenoid either works or doesn't the pcm tells the tcm that it needs to shift so tcm does that to solenoid. but it will set an engine code if that happens. for reverse there is no solenoid it's a valve because reverse takes more pressure to apply a clutch than forward. Even if it says a solenoid is bad doesn't mean it actually is because if the seal or clutch is bad will not allow the solenoid to shift anyhow.with the mileage on your car have a trans guy look at it. if you don't want a rebuild you can always get a junk yard trans. However you should have it professionally checked to make sure that is the problem.

Thanks for the help!

:cry:
I can't afford to take this BACK to the shop because I was in Hurricane Katrina and we are using what money we do have on rebuiling our lives. I have health issues, like lupus and RA which prevents me from being able to take it to a shop right now. Would this be something I can do myself?

Here's my delima.. I have a 1996 Dodge Neon that just started having a really high idle on start up. The check engine soon light stays on.. (always has) the instrument panel works when it wants to. So I'm not sure on the exact milage. And the shocks are gone! I wouldn't give this car away. I will never own another Dodge Neon! :x

What would cause this to have a high idle at start up and literally drinks gas by the gallons?? After the car warms up it idles back down the way it should.

Any suggestions would be greatly appreciated.

I had a vehicle that would idle high. I found that a sensor connector deteriorated. Some electrical tape was all it needed. Check all your sensor connections, especially for speed and idle. Hope this helps.

:) Thanks so much Primo

This just started all of a sudden. It would use 1/4 of a tank of gas only going 10 miles down the road.

I will check those. I wasn't sure if it could be a vacuum line or sensor. I think the dern thing has a mind of it's own....

Thank you and have a Merry Christmas!
Teressa

I would look at the throttle position sensor, usually its on your throttle body or intake manifold. For some reason 96 neons have a gauge problem your one of 4 I have heard of in the past couple months, the first car I looked at it was a loose connection in the back of the gauge cluster. Hope this helps

after it runs for about 10-15 minutes rather driving or sitting idle, something start to revved up really loud. the fuel filter was changed, air filter was checked, and it was also checked for debris and air. granted, the car has been sitting unused for over a year.

How long since a tune-up? Check for applicable mil codes, you can check those codes, yourself. You turn the key just till the dash lites come on, no crank, Cycle the key on--off, on--off, on, then the mil starts flashing, you count the flashes to get the codes. Your looking for two digit codes.

Possible vacuum leak?

I changed the shift solenoid on the front of my transmission. Know it idles very high .And it goes up and down.what is my problem.

Hi,

Idle speed on this vehicle is controlled by the idle air control motor. It is mounted on the throttle body. Make sure the wiring wasn't damaged or the plug disconnected.

If the wiring all looks good, here is a link that explains how to service it:

https://www.2carpros.com/articles/idle-air-control-valve-service

Here is a link that explains in general how one is replaced:

https://www.2carpros.com/articles/how-to-replace-an-idle-speed-control-motor-iac

If everything looks good, here is a link that explains how to replace it. It is specific to your vehicle. The attached pics correlate with the directions.

_____________________________

2002 Dodge Neon L4-2.0L VIN C
Procedures
Vehicle Powertrain Management Fuel Delivery and Air Induction Idle Speed/Throttle Actuator - Electronic Service and Repair Procedures
PROCEDURES
REMOVAL
When servicing throttle body components, always reassemble components with new O-rings and seals where applicable. Never use lubricants on O-rings or seals, damage may result. If assembly of component is difficult, use water to aid assembly Use care when removing hoses to prevent damage to hose or hose nipple.
1. Disconnect negative cable from battery.
2. Remove electrical connector from idle air control motor.

Fig.17 Servicing Idle Air Control Motor

pic 1

3. Remove idle air control motor mounting screws.
4. Remove motor from throttle body. Ensure the O-ring is removed with the motor.

INSTALLATION
When servicing throttle body components, always reassemble components with new O-rings and seals where applicable. Never use lubricants on O-rings or seals, damage may result. If assembly of component is difficult, use water to aid assembly Use care when removing hoses to prevent damage to hose or hose nipple.
1. The new idle air control motor has a new O-ring installed on it. If pintle measures more than 1 inch (25 mm) it must be retracted. Use the DRB III Idle Air Control Motor Open/Close Test to retract the pintle (battery must be connected.)
2. Carefully place idle air control motor into throttle body.
3. Install mounting screws. Tighten screws to 4.5 Nm (40 in. lbs.) torque.
4. Connect electrical connector to idle air control motor.
5. Connect negative cable to battery.

_________________________________________

I hope this helps. Let me know if you have other questions.

Take care and God Bless,

Joe