Car accelerating on its own

21 years ago

Hi! First time poster here and am sure hoping you can help....

This morning a very strange and scary thing happened. Less than ten minutes after leaving home, we were driving down the highway, where the speed limit is 70, when suddenly something didn't feel 'right' and I noticed the car was going that fast without my foot even touching the accelerator--it felt like cruise control racing up a hill, only we weren't on an incline, and my car doesn't feature cruise control!--and it didn't seem to want to slow when the brake was applied. In desperation I pushed on the brake pedal hard as it would go, pulled the emergency brake, and got onto the roadside, where I shoved the gear into Park.

I got out and checked that the mats nor anything else were interfering with the accelerator, and when I tried jiggling it, it felt normal.

Hoping it was merely a very weird fluke, we proceeded on our way, and about 10 minutes later the very same thing happened. Only this time it was more difficult to stop, and when thrown into Park, the motor surged loudly and died.

Our mechanic came soon thereafter and checked that cable under the hood that operates the gas. At first he suspected the cable might be fraying and catching, but he checked, and that was fine. He sprayed it with WD-40, and couldn't find anything wrong, so he followed me all the way back home, and of course then the car handled perfectly!

He did caution me, though, that in the event it happens again, to switch the key off and put it into neutral and veer carefully off the road.

Now I'm afraid to drive it, though. Luckily, this occurred on a rural highway. It would've been awful to be in town, surrounded by other vehicles and maybe even people!

I just don't understand it. Plenty of times I've had other cars die on me, but never one try to run off!

By the way, it's a '99 Mercury Tracer.

Thank you for listening!

Twinklenose

Featured Answer

brianl703

21 years ago

The symptoms the car is exhibiting could only be caused by additional air being admitted into the intake manifold.

There are three ways this can happen:

1)The throttle butterfly is open.

2)The idle air control valve is open.

3)There is a vacuum leak.

#1 would seem to have been eliminated as the cause of the problem by the checks that the mechanic did.

#3 would also seem to have been eliminated as the cause of the problem by those checks. As well, a vacuum leak large enough to cause the engine to accelerate on it's own would cause serious drivability problems (I'm talking bucking-bronco type serious) and would turn on the check engine light.

So we are left with #2, which seems as the most likely cause of the problem because in both reported instances it happened after an operating condition where the idle air control valve was being commanded fully-open by the computer.

Sort by:Oldest

Comments (46)

bulldinkie
21 years ago
Sounds like your pedal stuck.Did you look to see ifrug or anything else may have gotten under pedal,had it happen once
brianl703
21 years ago
Sometimes the idle air control valve will stick. It's a $50 part that takes about 5 minutes to replace.
Related Discussions
'Every Generation Makes Its Own Mark'
Q
Comments (25)
I am not disagreeing with Laag's take on sustaining lawns in his local conditions, but I think he glosses over the extent that most homeowners feel compelled to expend resources on keeping their lawns green and weed free. An awful lot of chemicals get applied to lawns to kill grubs and weeds, that also wind up in the local water supply. It may also be a matter of semantics, but the rainfall levels he cites are necessary over the entire year to keep grass evergreen and growing, and do not reflect what is needed to keep grass alive and growing in the southwest, or parts of the midwest and southeast. It takes much more water than naturally available to keep grass green in much of the USA, and most people who have lawns are unwilling to accept a brown lawn in summer, or use species that might go summer dormant under low/natural rainfall amounts. In these parts of the country, there are definitely other plants besides turf grasses that can remain presentable at height of summer and use less water. Even the trend towards using supposedly low water use Dwarf Tall Fescues is a bogus ploy to continue planting lawns here in California, in my opinion. They still need too much water to make sense as the predominant plant cover in our local climate. While much of wild California can also be considered natural grasslands, and survive on even lower rainfall amounts that Laag cites, they can not be maintained as mown, evergreen surfaces without huge amounts of additional irrigation. Even the really drought tolerant species that can serve as mown lawns, such as Buffalo Grass, will go winter dormant here in California, and don't satisfy the urge to have a year round green landscape. If we are talking about lawns as a ground cover that is to be maintained without irrigation, will be mowed, and is expected to remain evergreen during the warm months, there are few parts of the country outside of the far north and wetter northeastern USA that will sustain lawns as the American public prefers to grow them. In my opinion, in these parts of the country, and especially here in the arid west, lawns just don't make sense as a sustainable garden practice. I predict they will continue to lose popularity as the default plant choice in areas where water is in short supply, and cities are usurping agricultural water supplies here in the west so that cities will not have to ration water. So far, the water continues to be available for urban users to use as they prefer, but since over 70% of urban residential water use is used to irrigate gardens, the cost is going to get so prohibitive that people will vote with their wallets, and lawns will disappear over time. Perhaps there will be a trend towards using winter dormant Buffalo Grass and similar for people who must have lawns here in the arid west, but even the subtropical lawn grasses such as Bermuda grass or St. Augustine grass require regular summer irrigation to keep them alive here. I highly doubt that the vast American public will agree to keeping lawns in their future if it costs them over $300 a month to irrigate them, and few will be willing to have a summer dormant lawn that greens up again in winter, which would be the default condition here in California without irrigation. I also predict that ground cover alternatives similar to lawn will continue to become more popular here in the arid west, with homeowners converting to mowable Carex species such as C. pansa and similar, which can get by with less than half of what a Tall Fescue lawn uses to stay green. I have often tried to interest garden design clients in using very drought adapted turf species such as Kikuyu grass, Pennisetum clandestinum here locally, but few are willing to accept the aggressively spreading nature and coarse wirey texture of this grass. Not even when I explain that this is a grass that in my local coastal northern California conditions can remain green all summer with absolutely no summer irrigation, when it has clay loam soils and receives some regular summer fog which moderates the summer temperatures as well as significantly reducing evapostranspiration. I have also had great success planting lawn meadows using Carex tumulicola, which only needs mowing once a month, and can remain green with just once every 2 month irrigation in summer here in coastal conditions. At least here in California, I think that fescue lawns are a dying breed, and will be replaced with something else as the cost of water continues to climb, and possible mandatory limits on landscape irrigation are imposed across the state. I don't see this as environmentalists running amok, but just plain common sense, and dealing with the local conditions as they are, rather than applying some design sensibility inherited from regions where grass actually grows and survives without irrigation.
...See More
car insurance - rental car coverage
Q
Comments (3)
The liability might not automatically cover the rental car because somebody else could be using your car while you are gone, meaning you'd be insuring two cars for the price of one. It depends on the laws of your state. If your agent says that liability DOES extend to the rented vehicle, ask them to point it out in your policy. When it comes to insurance, if it's not in writing it isn't true. Credit card coverage is usually very good, but again be sure to read all the fine print. There are likely to be "exceptions" and "exclusions." Plus, it usually covers damage to the rental only. Keep in mind that even though credit card coverage would pay for repairs, the rental company will still want to collect the daily rate from you while the vehicle is out of service. Typically, the insurance will NOT cover that.
...See More
What cars have you owned/driven?
Q
Comments (33)
1929 Model A Ford, 4 dr with window shade, roll-up, style curtains on rear side windows. Color black - was there any other color? 1949 Plymouth, 6cy, 2dr, 3-sp manaul, column shifter, Blue, the last of the fast back designs. (Horrible rear visibility) 1954 Dodge, 4dr, w/ Red Ram V-8, 3-sp stick. This one was not a large displacement engine, rated only at 140 hp, but was the smoothest running engine that I have ever owned. Color: White top over Blue bottom. 1960 Plymouth Valiant, slant six, 100 hp, automatic, 4 dr, blue. Low torque engine - couldn't get out of the way of itself. Good fuel mileage. No power steering - didn't need it - very good handling. The next year, a longer stroke engine was offered with much more torque. This one was very driveable and became the engine of choice. 1964 Dodge Dart, 273 cid V8, 4 dr, automatic, white w/red interior. This one was a good compromise between, power and fuel economy and room. I wish that I had another similar car today. This one was well liked. The engine was a thin wall cast version of the 318, but with a smaller bore. The bore centers were the same as the 318, thus it was manufactured on the same engine line as the 318. Many engine parts were interchangeable with the 318. 1969 Dodge Coronet, 4 dr, 318 cid V8, blue Just an ordinary sedan to hold my growing family. EPA fix-ups began to appear and degraded performance a bit without any fuel mileage increase - lower compression and a low ratio rear end ( 2.71 to 1) Though I put 115,000 miles on it before moving on. 1974 Dodge Sedan, 400 cid V-8. EPA had struck this engine hard. It was based on the admired 383 V8, an engine upgrade option for station wagons and police cars. To meet EPA requirements, Chrysler lowered the compression ratio and installed a very mild cam. The resulting power was so embarrasing that chrysler bumped the displacement up to 400 cu in to gain back a bit of performance. (An earlier 383 in good tune would run cicles around it.) 1974 Oldsmobile Cutlass, 4 dr, V8. Bought used for a 2nd car and commuter. Had to put in a valve job after 1 yr ownership. As it neared the end of its life, sold it to a junk yard. I didn't want to see this on the road again as it had become dangerous. The body metal holding the rear body mounts had corroded away. The best part of this car: The radio. 1975 Buick Apollo, 270 cid V-8 (Oldsmoblie engine), 4 dr, Yellow. The smallest V8 made by GM. Not a good car. Was purchased as 2nd car for a winter-beater and comuter. Let my kids learn to drive with this one - they were not going to win any stop light drags with it. In fact, they were lucky go to get across a big intersection before the light changed to red. I bought this car during a period of runaway inflation. It was 3 yrs old and loosing value at a lesser rate than my hard earned cash in the savings account. That became part of my rationale for picking it up for a 2nd car. 1976 Buick Estate Wagon, 4 dr, 455 cid V8, Clam shell rear gate and window; 19 ft long! This one was the family land barge and vacation machine. The family had now grown to 5 and this station wagon held us all in comfort on long trips. This was the first year that GM put catalytic converter on all of the Buick line. (GM had put catalytic converters on a few select models the year before as a field trial.) With the converter, Buick put in a better cam and iginition advance curve and got better power plus 2 more miles per gallon. I garaged this one every winter taking it off the streets just before road salting began and it stayed off until next spring after a rain had washed away the salt. I kept this one 13 yrs and it was in very good condition the day I traded it in. It was showing signs of a catalytic converter plugging up, otherwise, the engine was in fine shape. 1980 Chevrolet Citation, V6, 4dr + hatch back, green, my first front wheel driver. A fair car. Had a very good useable interior layout and driver visibility - wished there was a car with those features today. Had too much braking on rear wheels compared to the front - gave the car a tendency to swap ends while braking on slippery surfaces. Over- sped the engine one time when the tranny failed to catch 2nd gear on a downshift - it went all the way to 1st gear at 45 mph. Loosened a rod bearing. GM got the steering geometry right on this one - no torque steer. The Chrysler K-car was plagued with torque ateer. 1983 Chevrolet Citation, V8, 4dr, white Engine was de-tuned a bit, but otherwise the same as the 1980. 1981 Pontiac Phoenix (twin of the Citation), 4 cy "Iron Duke", 4 dr., Brown. A dog. Served as a commuter. When climbibng a grade, engine vibration could be strongly felt in the steering wheel - each firing of the cyliners were perceptable. No. 2 son, a new driver, burned the engine up while driving home from a days outing with the guys. He had not been watching the oil level - it ran out. 1989 Dodge Dynasty, 4 dr, V6, Light blue 1st yr for Chrysler's new computer controlled transmission. It had issues - shifting algorithm should have been revised. It was programmed to give good results on the EPA fuel mileage test, but otherwise, was bad for commuting traffic. Car was too softly spring - people riding in back tended to get car sick. 1992 Dodge Dynasty, V6, 4dr, White. A much better car. Better handling. Held front alignment very well. Shifting algorithn improved, but still had glitches. I put 90,000 miles on it and sold it (cheaply) to my daughter. She moved out of state and later sold the car to her friend. By then, the rocker panels were holed out. I saw the car two years ago and it was still running with upwards of 140,000 miles on it. 1992 Jeep Cherokee, inline 4.0 L 6CY, 4dr, with part and full time 4-wheel drive, Red. Really liked this one. Gas mileage wasn't great, but it took us all over the lower 48 states and into places where an ordunary car could not go. We photograhed many interesting scenics using this vehicle. This one was my prime winter time driver - great in snow - can't beat it. 1998 Dodge Stratus, 4 cy, dual overhead cams, 4 dr, red. An OK car - not great, but OK. Its gets very good gas mileage on trips and that is what I bought it for. Runs great. I beem garaging this one very winter and there are no rust spots. 1998 Jeep Cherokee, in-line 6 cy, 4 dr, again with part and full time 4 wheel drive, Deep Amethyst Purple (appears black under many lighting conditions). Replaces the red Jeep which was getting body rust, but ran well - had 190,000 miles on it.
...See More
car sounds like it's revving
Q
Comments (4)
If you have a tachometer, what was the rpm and approximate outdoor temperature? Newer models (less than 10 yr old) with 4 cylinder engines may idle at 1200 rpm when first started in cold weather (20 F or less). The idle speed should pull back to about 700 rpm as the engine warms. What make an model do you have? Older Jeeps have 2 cooling fans: one belt driven through a viscous clutch and an electric fan. On start up, the viscous clutch is fully engaged and the fan is noisy. If the fan is cool or cold, the viscous drive will gradually reduce and the fan will become more quiet. This noise is more noticeable when the observer is outside the car.
...See More
twinklenose
Original Author
21 years ago
Thank you both so much for answering.
Yes, Bulldinkie, that's the first thing that crossed my mind as well, but nothing was in the way.
Brian, I'll ask my mechanic to check for that part. Thanks!
I was beginning to wonder if the car hadn't become possessed, or maybe it was 'mad' at me, or showing off, since we just got it paid for!:)
Twinklenose
Janis_G
21 years ago
Twinkle, do not drive that car til you get it fixed.
A terrible thing happened here in my town.
A man was driving into a tire place to have his tires checked.
His car did what your's did and he couldn't stop it.
He ran over a customer cutting off both his legs.
It was awful.
Please be careful.
twinklenose
Original Author
21 years ago
Oh, my gosh, Janis!!--I was nervous enough before, so am certainly taking your advice to heart! Thank you for posting such a concerned warning!
Twinkle
earthworm
21 years ago
Posted by: brianl703 (My Page) on Thu, Jun 30, 05 at 10:24

Sometimes the idle air control valve will stick. It's a $50 part that takes about 5 minutes to replace.

It should take about an hour( or more) to do a proper diagnosis, and this must be done to assure that indeed it is an idle air control problem and not something else..

It is not cost-effective nor safe to guess, no matter how likely !

I wonder if the engineers at the car-makers test these devices - to make them fail safe as possible and repairable...Also, very important, is to establish diagnostic procedures that are effective and economically feasible...
earthworm
21 years ago
Back in the 80s or 90s, the Audis were doing this, and I do not,as yet, know exactly why..
And since human life is at stake, it behooves us to know , scientifically, exactly WHY !!
No question, IMO, some people panic and hit the gas by mistake when they wish to brake...
This may be impossible to solve
twinklenose
Original Author
21 years ago
Brian--I found a drawing of this valve online. Could you please tell me approximately where on the engine the real thing might be located? Is it usually easy to reach?

...And just wondering, but is this something a novice could easily replace? I've replaced a fuel filter before (different car).

Thanks again--
Twinklenose
brianl703
21 years ago
It'll be located on the throttle body, which is where the throttle cable is attached, along with the air intake duct from the air filter.

Yes, a novice could certainly replace this part. On the Escort/Tracer, there isn't anything in the way that I can recall.
gmatov
21 years ago
I am not an ASME member of anything, but the idle air valve, or idle stabilizer valve passes a very small amount of air, barely enough to stabilize the engine at idle. It may even be cut out of the circuit at anything over idle speed.

You seem to have another problem, possibly to do with the engine control unit, the computer.

As to the Audi "runaway acceleration", the TV crew had to gimmick the car, similar to the Chevy truck fireball scene to reproduce it so they could dramatically show how evil the cars were. It appears that the culprit was gas and brake pedals set more closely together than on the typical US car. People were pressing the accelerator and swore they were STANDING on the brake.

Bought my first Audi at 10 cents on the dollar because they were so undesireable in those years, still driving them.

You DO have a serious problem.

Has anyone worked on the transmission in the recent past?

There was a case of a bolt put back in backwards in a tranny rebuild, where the threaded end of the bolt stuck up too far and interfered with the accelerator linkage and locked the car in full throttle.

Good luck with the problem. Now that it's paid off, mebbe you should get rid of it.

Cheers,

George
brianl703
21 years ago
I am aware of at least one reported instance of a faulty idle air control valve causing the vehicle to accelerate on it's own. The specific case I recall involved a Ford Taurus and happened after the idle air control valve was cleaned. (Ford doesn't recommend cleaning them--maybe that's why.).

It definitely is not cut out of the circuit above idle. Above idle, on Ford vehicles, it is fully open so that the computer can gradually close it so as to provide smoother deceleration if the driver lifts completely off the gas pedal.
janie_ruth_holt
19 years ago
I was over my sisters apt and was sitting in my car, my car was in neutral with the emergency brake on, I have a 5 speed, Kia Spectra. THe car was in idle started to accelerate on its own, I turned my car off and restarted and it was ok for about 2 minutes then it did it again and I repeated the turning of the engine off then back on, at that time the check engine light came on. I got brave and drove it home and the check engine light remained on. A couple of days later I was going 70 mph my crusing speed,(I don't have cruise control) as I was traveling on 265 my car started to accelerate on its own, it kind of scared me at first because I was up to 82 mph, at that time I merged into the righthand lane I engaged my clutch and put the stick in neutral and turned the car off and then restarted it. It seemed to be ok because it did not do it again. The next day it was dropped off at the Kia store. I had it in the shop before for this problem, and they adjusted the throttle cable, Can anyone help me with this because the shop gave the car back to me and sad that there is nothing wrong and it didn't act up on them. I know something if wrong with this care. I dropped the car off again today. Any suggestions that I can pass on to the Kia place to try. I'm getting very leary of driving this car. Thank you for any suggestions......
glenarklet_o2_co_uk
15 years ago
My BMW 5 series is doing the same thing at moment. I have it sitting idle and then the car starts to accelerate on it's own as sson as I put power in and take foot off pedal. Accelerates from 700rpm to 5500rpm in less than one second. MMmmmmmm.
bronwynn_09_hotmail_com
15 years ago
I have a 2000 Toyota Echo....Just bought it and of course as soon as i get it home, it started acting up! THere is no cruise.
When its in park it's starts reving and wont stop unless i turn it off or sometimes when I press the gas and Rev it myself. When Im driving it acclerates by its self. I could drive for miles going 40 with out touching the gas.
When im going 100 it will slow down to 60 or 50 when my foot is off the gas but then it will stick at those speeds and not slow down.
It will always come to a stop when i press the brake.
When im stoped at a stop sings or lights it's so eager to go....It's like it has a mind of it's own, it dosen't like to be still.
What could this problem be....
becky_vigil_neal_yahoo_com
15 years ago
I see that this was posted a while ago, but I thought I'd ask if you have gotten this problem fixed. I have been having the same issue with my 99 Honda Passport. At least 5 mechanics have looked at it and cannot figure out the problem. All of the causes listed by other people here have been checked out and parts replaced but it still acts the same. Let me know if you have figured out what's wrong with your car.
Albert87reyna
14 years ago
I seam to be having the same problem with my 2003 Impala, i as well have checked all those things and we still cant find out what's wrong with it, but i did notice that if u disconnect the MAP sensor it stops doing it. So i replaced it and it keeps doing the same thing... So lm certain that it has to do with a sensor or something, but if i find out the problem first ill post it cuz i know its stressful situation and expensive to be guessing and buying parts that aren't it...
westranch
13 years ago
This could have something to do with the recent potential Ford recall of Sable/Taurus? Maybe Tracer will be involved as well. The recall is concerning stuck accelerator mechanisms.
polarelec
13 years ago
This problem has been resolved with certainty on one car I've travelled in as passenger.

The valves of the cylinder head were staying partially open (a very tiny amount). This causes compression and combustion leaks up the inlet valve side, into the fresh air inlet manifold and increases the air pressure there. The sensors (often called MAP) are partly responsable for the conclusion in the motor computer that the airflow is suddenly more free, as if the driver has fully opened the throttle letting a lot more air into the manifold. The MAP value is used in the computer to seek a proper mixture (along with oxygen sensor and other temperature measurements). To get optimum mixture with what the computer thinks is now very much air . . . . it injects more fuel immediately and far more than the idle speed value. Result . . . the car accelerates on its own, no matter what you do with the throttle position.

Solution. You may have a car with hydraulic tappets or used to. Many newer models are going back to manual adjust tappet clearances. If that's confirmed good then sticky valves (dry or overheating) need be investigated. If you use very clean petrols or LPG Liquified Gas they often lack the oiliness that helps valve function and with LPG due to hot, lean combustion the valves can wear drastically and recess far more than usual into the cylinder head or have uneven wear.

So, it's tappets and valves and that's why the problem doesn't show up on diagnostics nor is it always going to occur and if you stop the vehicle before inspection . . . the problem may have disappeared. Computers, lambda sensors, throttle bodies, cables, electronics and everything else a technician can change out . . . are usually in good working order. It's a mechanical problem in the steelwork of the engine.

Disconnecting the MAP can work to get around or get home. In the case of Daewoo that works because the engine computer switches immediately to TP mode (Throttle Position mode). It may not be so precise in power, may stall or idle rough, may have emissions outside the regulations yet it can stop this particular cause of sudden accelerations. It's a legitimate mode for driving yet may cause long term problems to oxygen sensors and other parts expecting a more precise mixture of air to fuel. I'm unaware of the effect of disconnecting the MAP on other makes and models of cars.
john999
13 years ago
The engine needs more than just air, it needs extra fuel as well, otherwise it will run lean. More fuel is only added when the throttle cable is operated.

The Echo sounds like a vacuum problem ; there is a leak, possibly in the air intake, and the computer compensates for the lack of vacuum by opening the butterfly valve, rather than using the idle circuit when idling.

The Tracer is a Mazda, and unrelated to the Taurus. The recent Toyota recall was for a plastic accelerator pedal that lacked a nylon bushing (to "save" money) and so would "stick" on the mould line of the two parts of the pedal.
Once the engine starting running flat out, the transmission selector could not move because the high fluid pressure prevented the spool valves in the control block from shifting, and the brakes were ineffective (normally, the transmission will slip into neutral when the brakes are applied, but the high fluid pressure prevented this).
krhillman
13 years ago
I have a 2005 Grand Am V6 with 177k miles. It has the following symptoms:

--"stuttering" when accelerating from a complete stop. Worsens after highway driving. Has been occurring for over 2 years.

-- at highway speeds, revs up from 1800rpm to 2200rpm, then back down to 1800rpm repeatedly. This does not occur when driving the vehicle in 3rd gear. It has been happening for about 1 week and getting worse.

--engine frequently revs up to 1600rpm when in "park" and goes down to 900rpm in "drive." This started yesterday.

--engine frequently accelerates by itself or maintains speed with foot off gas pedal while driving between 20-60mph, and is ready to jump off the line after a stop. This began yesterday.

--Restarting the engine temporarily stops the revving while in park.

Any ideas will be greatly appreciated! I just want to know what I might be looking at before taking it in to the shop :) Thank you, Kristine
Emily1993
11 years ago
I drive a 2002 Hyundai Elantra 5 speed standard.
When i bought the car it was in great condition, about 6 months after it started surging on me when i was in neutral and would go from about 700RPM to about 5000RPM and then drop and spike repeatedly. I drove it for a while, had a bad clutch on the car so id just leave it in gear and with my foot barely on the clutch it would idle at about 700RPM like normal. A few months after that it stopped spiking and just would climb from 700 up to 5500 when idling. I just got a brand new clutch installed in my car and obviously my cheat way of getting it to stop is absolutely not an option anymore. Anyone have any idea what it could be? Vacuum leak crossed my mind as the head gasket needs to be replaced. Checked the throttle cable. I literally have to turn my car off at lights if i need to drive anywhere! and who wants to do that?! I need some help to get this diagnosed so i can fix it as soon as possible.
polarelec
11 years ago
If your vehicle is beta1 1.8 or 2.0 you have hydraulic valve lash adjusters. If your vehicle is beta2 you have mechanical lash adjusters.

Without the proper adjustment, or due to valve sticking, compression gases can leak back up into the air inlet manifold, increase the pressure, confuse the control computer that it's because the driver has opened the throttle wide and so it may choose to add more fuel. Surges are the result.

I remark "may" because most control computers are equipped with a throttle position sensor (to know where you really put the throttle), yet, believe it or with difficulty, some control boxes' softwares place more influence or emphasis on the inlet manifold pressure anyway, as if more important than where you place your foot.

On some vehicles with the MAP (manifold air pressure) sensor, it's possible to simply disconnect it, to get to a garage or safe place. On the Daewoo the MAP is right on top of the engine, just underneath the hood. The engine restarts in a more basic, less, um, nervous mode called TP. Hyundai may be similar or identical.

Garage techs do know of problems with valves on your model and even shim them . . . . . . nothing new? It's like the sixties!

http://www.automotiveforums.com/t729731-discuss2002_elantra_valve_noise_.html

regards

Here is a link that might be useful: valve adjustment still matters
PRO
joannescheid2
11 years ago
My new Jeep wrangler 2015 suddenly accelerated on the highway last week. We were driving for about an hour when there was a click feeling under my foot that my right was resting on our gas pedal keeping the 60-65 speed. Directly after that click feeling I then noticed the speed increasing as the pedal moved away from my foot and depressed? The engine began accelerating. I had not even figured out the cruise control nor am I a fan of it since we lived in a congested area. I thought that the cruise control somehow thought it was in control? So I Tapped the brakes. This caused a slight pause in the Jeep's climbing acceleration until I released the tap and the car surged forward. Climbing to speeds above 70 I began to roll through my options as I depressed the break hard. The car slowed a bit to dip below 70. Again I tried to release again the break whilst I and noticed the gauge and the throttle was in the red and climbing via the dial on the dash. No other illuminations giving me a clue. I began to both depress the break and pull the emergency break simultaneously. Then the car slowed allowing me to pull over to the emergency lane to turn off the engine. The gas pedal was completely depressed. Stuck to the floor prior to turning the engine off. There was no floor interference as our mats are buttoned in with a peg system. Both my passenger and I visibly could see the pedal was flush to the floor. Nothing was inhibiting the release. It was like pulled in? I tried to squeeze the tip of my sneaker under the pedal. Zero room to do so. Just as I was turning off the engine the dash illuminated a red lightning bolt? Once the care was off the pedal released. I turned on the car and everything was reset? I called for a tow. Car still at dealer. Dealer/Chrysler still investigating. Never heard of this happening I was told by both. Any ideas? I am in my 40's and quite healthy and a corporate software executive and drive approximately 30k per year. I know these cars have computer dependent systems. I am thinking something was not tripped to allow me to regain the throttle? This is my second Jeep. Last one was purchased in 1990. Any ideas? Brian??
bobkel
11 years ago
I have no ideas. BUT make sure you file a report with NHTSA. That way everything will be on file. And also it will be added to any other incidents if there are any. Good Luck.
Bob

https://www-odi.nhtsa.dot.gov/ivoq/
PRO
joannescheid2
11 years ago
Thanks Bob. Already filed a report. 10 days later and no call back from Chrysler they are still trying to assign someone.
Angela Storm
11 years ago
Ok can some one please help me i have been having trouble with my car and i dont know what is going on. First it started the one day when i backed up in the drive way and then put in park the car sat there like i had the foot on the gas then the rpms were up to 2 so then i turned it off and started it back up it was fine. Well now my car sits at a light and the rpms go up and down and the car sits there like i have my foot on the gas and i dont . Also it shakes a little when sitting it dont ride smooth. And the last part when i am driving some times like at a light i will take my foot off the break and the car will start moving on its on i dont know what to do help please
PRO
EGL Inc.
11 years ago
Sudden Acceleration

The symptoms the car is exhibiting could only be caused by additional air being admitted into the intake manifold.

There are three ways this can happen:

1)The throttle butterfly is open.

2)The idle air control valve is open.

3)There is a vacuum leak.

Number 3 is what I believe created my Sudden Full Out Acceleration!

I just drove my 2007 Hyundai Sante Fe home from the dealership for having a recall fix. New cylinder cover gasket and alternator. On the way home the car suddenly accelerated, full throttle. After forcing the vehicle into neutral and turning off the engine, I let the car stop on the shoulder. I restarted the car, and it idled just fine. I then carefully and gently applied the accelerator, and when I reached 30 mph it shot up to full throttle instantly. Again, I put the car in neutral and turned it off and glided into the nearby Holiday service station. My Hyundai dealer sent out a manager and a mechanic.

He tightened up a couple of grounds and found the accordion style rubber manifold tube going to the MAP sensor was off the manifold. He put it on securely and everything operated correctly.

I can speculate some one leaned on the air sensor mechanism and unsecured the rubber air vacuum tube to the manifold. Now this tube is a firm rubber tube that held itself onto the manifold connector. However, after I drove for a half hour or so, the rubber softened from the engine heat. The engine moved under torque creating a vacuum leak allowing more air into the MAP sensor which told the EMC to send more fuel which resulted the car immediately accelerating to full speed. Once this was secured, no vacuum leak, no more problem. (Please note there was no problem until the rubber hose heated up and softened as the accordion style put enough pressure on the connector, holding it in place up to the point of sudden acceleration a half hour into my trip home.)

I suggest everyone check this connection to assure this does not occur to them. Also, I am going to ask the dealer to have their mechanics check this before releasing the car from the shop. Lives depend on it. My wife would have not had any idea how to stop the vehicle in this situation and the results could have been tragic.
Haley Woods
10 years ago
I have a Chevy s10 and its doing some weird stuff. When I'm parked the engine revs on its own and when I begging to go its like I don't have to press the gas at all and it will start going up to 20 mph. Help?
jgarcia321
10 years ago
last modified: 10 years ago
I have a Jeep Liberty with the same symptoms, high acceleration at IDLE and would let go off the pedal on the freeway and it would keep going the same speed or higher. I read these posting and replaced the idle air control valve and the symptoms were fixed. thanks
Fabian Enrique Arguello
10 years ago
Have a 97 BMW i52.. It is accelerating while in park and driving on the road by its self .. It accelerates very quick and lots of power behind it. Could you please give similar fixing solutions to this problem .. Its very dangerous...
gooserbear
10 years ago
Here it is 2016 in April and I am posting on here on behalf of my boyfriend who has my old car/my mother's old car. It is a 1997 Chrysler LHS and the random accelerating just started happening last week. My father checked under the hood, and checked for something causing the gas pedal to stick and nothing came of that. My dad sprayed underneath the hood I believe with WD-40.

We took the car to a repair shop and they took about two days (not including the weekend due to being closed) and today called and said they repaired it and took it for a test drive and the problem was all fixed, but as soon as my boyfriend went to drive it he said it felt like it was just accelerating more than before and this time more forcefully.

I believe the part they replaced was the "idle motor" with a brand new one...

The car is now at the repair shop again with the same people as before...

please help!
lovetogarden
10 years ago
last modified: 10 years ago
I know this is a very old post but I just have to say that turning the car off is the absolute worst thing you can do, because it will stop the power steering and power brakes. The best thing to do is to put the car in neutral, and apply the brakes, while you are steering the car to the side of the road. If you can, get your emergency lights on. Only when you are on the side of the road do you pull the emergency break and turn the car off if it still didn't stop. Hopefully, the car will have slowed down some when you do this.
gooserbear
10 years ago
The car is still accelerating on its on and even Chrysler doesn't know what's wrong with it.
lovetogarden
10 years ago
Does your car have cruise control? It could be a malfunction with the cruise control since it is also has wires running to the accelerator. My mother's car kept doing that until we found out that she had the switch on without realizing it. Even though you are supposed to push the reset to regain the speed after breaking, for some reason her car wasn't doing that and would just take off on it's own. In her car's case it wasn't even a fix. It was simply a matter of turning the switch off and making sure it stayed off. The placement for that switch is on the same knob as the directional and the wipers. Very easy to inadvertently switch it on. That's why newer cars have cruise control in an area that can't get mixed up with other functions. I'd have them check that out too. If they think that is the problem they could pull that wire from the accelerator and disable cruise control.
Julie West
10 years ago
I have had something similar happen in my 2009 Ford Fusion SEL V6. I was driving around doing errands and then came home. I was pulling into a parking spot at our apartments when the issue happened. I had my foot on the brake and was nearly at a complete stop when my engine revved and jumped over the curb and into the apartment wall. With it being only 15 feet, I didn't have a huge speed and the airbag didn't deploy thank goodness. I have had people ask me if I didn't have my foot on the gas. Well, how could I since I was at a near stop and hadn't moved my foot off the break? I do know I stomped the break harder when it started speeding back up. I did not think to pull the emergency or put it in neutral. I have it in the shop getting the body fixed. But what do you think? Is this computer related possibly? Thanks! I am scared to drive my children in it and am in a pickle with buying a new car.
Patricia Marez
9 years ago
My car started doing the same thing today. My ex gave it to me. Broke up with me and today I was driving and the car just started going faster and faster. I could barely stop it. I had to use emergency brake. I'm disabled and have 3 kids so money is tight do you think the previous answers are the problem? I can't afford diagnostic and part and mechanic.
lovetogarden
9 years ago
Patricia, you say your boyfriend gave you the car? I'm assuming that was before you broke up. Is that correct? You don't think he could have done something like switch the wires on the cruise control where it is always on, do you? Don't mean to scare you but so many people are nutz today anything is possible. Anyway. what you are talking about here is an emergency situation that has to be check out by a mechanic. What I can tell you to do is to see if the cruise control is inadvertently on, as was the case of my mother's car. If that isn't the case you must bring your car in to the shop. And don't be pessimistic. It could be something simple and an easy fix. But you won't know unless you go. Besides, no mechanic is going to start any work unless you approve it. If you can't afford it maybe consider selling the car to someone who can fix it and buying something else. But whatever you do, the last thing you should be doing is driving a car you can't control with you and your children in it. BTW- do you have an honest mechanic you can take it to?
mehrez76
9 years ago
Hi all I'm having problem with my Peugeot 207 hdi 2006 comes up sing on dash board saying risk of particle filter blockage and triangle sign eny idea what coUldale b eny advice plz asap thanks
Chela Montes
9 years ago
Hi everyone. These postings are from awhile back but I need help. I own a 1994 Cobra Mustang and its had a lot of things replaced but always seemed better after. The most recent was the water pump and a tune up. I'll be replacing my air filter next and have my ac fixed as well. A few days ago while waiting at a stop my car sounded like I was pressing the gas and I wasn't. I even looked down to be sure or to make sure the gas pedal wasn't sticking. It was only revving barely above the 1rpm but after reading some posts I don't want to wait for it to get worse. Any advice on my particular car would be greatly appreciated... Thanks
jemdandy
9 years ago
If you want a response, do not tag a request onto an old post. This post is from year 2005. If you truly desire a reply, create your own new post!
Chela Montes
9 years ago
Ty
dflynn55
9 years ago
Writting from Ireland and owner of a 2015 Toyota Prius and while doinf a routine u turn in my housing estate I experienced "unintended acceleration" which resulted with the car crashing into a solid block wall of a house and it only took 4 seconds from the start of the u turn. I felt as uf the car had at least reached a speed of 60km but the Toyota engineer says it was only 20/25 and the car was at full throttle. The brusing marks from the 8 year old sitting in back seat would say differently. Does anyone know what speed can a car get from 0 in 4 seconds with the trottle fully engaged. I believe the car is a potential death trap and trying to build my case here as I know that with a 40 year clean driving recond, I dud not cause this accident to happy. Also the air bags dud not deploy?
Corita Welch
8 years ago
I have a 2001 Ford Expedition and I have a question about an issue that happened. I was taking my kids to an appointment and while I was driving, the vehicle wanted to accelerate to the point I couldn't get it to slow down while pressing the brake. I finally pulled over and immediately put the gear to park and turned the car off since I was terrified for my and my kids safety. I waited about 10 minutes and turned the vehicle back on to the point the idle went over 4000 rpm for about 3 minutes and then it went back down enough to drive it back home. What would cause this since this vehicle has done this twice now and it is getting to the point I am afraid to drive it thinking it is going to happen again since it has been very cold here in Kansas. What causes this and is there an affordable repair for this issue. Thanks Corita Welch
300ft_anin
8 years ago
hi corita, sounds scary!. you NEED to find out why your truck is doing that. there are alot of discussions online. unfortunately there could be a number of reasons. i copied a link to a ford forum, maybe read through it and something pops out. good luck and if driving your vehicle isn't necessary i wouldn't.

www.ford-trucks.com/forums/8860-accelerates-by-itself.html
tegmapat
7 years ago
I've had the same thing happen with my 2004 Impala. I can be driving along and notice that the car is picking up speed. With no foot on the accelerator the car will keep going faster and faster. One time I was driving along at 25 mph in a school zone and the next thing I knew, I was up to 70 mph and still going. Of course, everytime I took it to someone to try it out, it wouldn't happen for them. I'm so glad for the advice you've given here. I will have to have the air-control valve checked now. Even tho' it only happens occasionally, it's highly dangerous, that is for sure. It takes all my strength to brake hard enough to stop the car!

Car accelerating on its own

Comments (46)

Related Discussions

twinklenoseOriginal Author

twinklenoseOriginal Author

twinklenoseOriginal Author

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

twinklenose
Original Author

twinklenose
Original Author

twinklenose
Original Author