CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Stopping a car with a stuck throttle

On another website, the question was asked: “What do I do if my gas pedal is stuck and I can’t shift into neutral?” The response was, first, never shift into neutral and risk a blown engine. Then turn the key one position from on to accessory, brake to a stop and shift into park. For me that response is wrong on so many counts.

  1. A blown engine from shifting into neutral is far more acceptable than a high speed crash (IMO).
  2. If you’re still in drive, depending upon how much power your engine is making and how much brake pad you have left, you may not be able to stop the car before your brakes are gone.
  3. If you can’t shift into neutral why would you think you can shift into park)
  4. Most modern cars no longer have an ignition key, but rather a fob and a push button.

Regarding # 3 above, the questions become: a) if you can/do shift into neutral, will the engine shut off if you push the button, and b) if the engine does shut off, will that lock the steering wheel?

I have always heard that the first thing you should do if you’re driving and your throttle sticks is to shift into neutral (as noted in #1 above), then begin braking, move to the side of the road and then shut of the car. I’d like to get some opinions on this subject.

Why wait to brake? Use the brake, as hard as needed, and steer to a safe place. Then shut off the engine.

A few thoughts:

On modern cars, the “rev limiter” would prevent a blown engine resulting from shifting to neutral.

On modern cars, the brakes are powerful enough to overpower the engine, even if it is at full throttle. Yes, the stopping distance will be longer, but the fact remains that the brakes are more powerful than the engine.

On most modern cars, applying the brake will cause the engine to return to idle. Toyota was one of the last to add “brake override”, and in the wake of their “runaway cars” incidents, they even recalled older cars in order to install it.

Here is a video from Consumer Reports on this very issue, and their advice remains…
Shift into neutral and apply the brake.


:thinking:
3 Likes

I’m with you that I’d rather have a blown engine than kill someone, but knowing my car has a rev limiter, that’s not even a concern.

The chance of experiencing uncontrolled acceleration is pretty remote already, but it’s not so remote that it’s not prudent to think about and practice what you’d do if it happens. On the other hand, asking, “What if I can’t shift to neutral?” strikes me as paranoid.

It’s kind of like asking, “What if my engine explodes with no warning signs beforehand?” Sure, it could happen, but the chance is so remote that there is little point in planning for it. If something that unlikely were to happen, maybe it’s just your time.

So auto makers are already addressing this issue. Cool.

I turned off the ignition when that has happened to me. With any luck I’ll never own a car without an ignition key.

1 Like

Turning off the ignition can lock the steering wheel which it is why shifting to neutral is better.

3 Likes

If it doesn’t slow down when you take your foot off the gas, use the brake. Shift into N if needed and possible. But use your brake, first and always. Don’t turn the ignition switch at all until you have brought it to a stop in a safe place. Locking the steering wheel in a car that is moving is bigger trouble than an over-revving engine.

1 Like

The steering won’t lock without the transmission being in the park position.

3 Likes

On all (fully functioning) cars? Since when? I wouldn’t count on it, although I admit I have never tested it.

While performing repairs we leave the ignition in the “unlocked” or “accessory” position so that the steering isn’t locked and the front wheels can be turned left-right when necessary.

The ignition can’t be turned to the locked position unless the transmission is in park.

With a push button ignition system when the start/stop button is pressed with the transmission in drive or neutral to stop the engine, the ignition stays in the accessory position (the radio stays on), wheel alignments are performed in neutral, we experience this daily.

What about manual trans cars?

The ignition on a manual transmission car has a lever to push or the the key must be pushed in to overcome a detent in the lock to turn the switch to the locked position. The vehicle operator needs to know the the positions of the ignition switch; on, off and locked.

1 Like

On a manual transmission car? Push in the clutch.

2 Likes

They have a clutch, which makes all this discussion obsolete.

You mean moot. But still, if putting the trans in neutral is a problem for some, wouldn’t pushing in the clutch pedal present the same problem - overrevving an engine, maybe to its harm?

I still say the best option is, if letting off the gas pedal doesn’t slow the car down, use the brake.

On a car with a manual transmission, you don’t usually need the clutch to shift out of gear.

Using the clutch to shift into gear makes the shift smoother (and if you know how to float gears, you can shift from one gear to another without the clutch, but I don’t recommend it), but on most cars, you can shift out of gear without the clutch just by letting off on the gas and moving the shifter.

On my car (a '98 Civic), it’s not easy to shift out of gear without the clutch, but it can be done with a little effort.

So, if you have unintended acceleration on a car with a manual transmission, you have two choices to disengage the engine from the transmission:

  1. Press the clutch.

  2. Shift to neutral.

With an automatic you can just shift to neutral and hope for the best, but if you watch the video above posted by @VDCdriver, you’ll see that this isn’t your only option.

1 Like

Here we go again. Shift into neutral. Leave the key alone. Stop the car safely with the brakes. A modern engine has a rev limiter and the engine won’t blow up, but it’s a ridiculous question anyway.

Whose life is more important here? Yours or the engine? Maybe at your funeral everyone will complement your choice to save an engine.

4 Likes

I’ve never had a car that locked the wheel when the key was turned to the off position while the shift lever was out of PARK. And I’ve had more than one car jump to or stick at wide open throttle and ended the drama immediately by twisting the key. Bad battery ground, broken motor mount, broken throttle return spring, pedal hanging in carpet, etc, there have been many causes in the past plus the more current throttle by wire issues.

I suspect lots of people would be shocked into loss of control if the power steering and power brakes stopped working, which would happen soon enough if you turned off the engine. Sure, if you know it’s coming and you are ready you should be able to control things to a safe place and a safe stop, but once the car is in neutral who cares about the engine?

1 Like