[June1]

Has anybody experienced sudden unintended acceleration? It’s got to be the scariest thing that has ever happened to me in a car and I’m at a loss now as to how to proceed regarding insurance/ fault / the garage I bought it from etc etc. 2 cars have been written off
.
I’ve only had the car a week when it literally ‘took off’ by itself. Of course I know it sounds ridiculous but that is what happened. I’d be interested to know if anyone else has experienced this and wondered if somebody might know why this happens.

[Beelzebub]

@June1Peopke will need more detail to give even a guess.

What make/model? Auto or manual?

Full details of the collision, especially exactly what you were doing.

[June1]

Hi
I was driving a Renault Clio Extreme 2010 plate manual.
I had got into the car and did the usual routine to set off but something happened and the car shot off at speed. I was unable to control the car it all happened so fast. I smashed into a car parked on the opposite side of the road. I know it sounds like the craziest thing ever and I can understand how people assume driver error but I know I had no control over how the car accelerated. It all happened in the space of seconds. I’ve been told that Sudden Unintended Acceleration is a thing but how can that be proven?
i was interested to see if any drivers on here had experienced anything like it or knew somebody who had.
Many thanks

[Beelzebub]

OK Is your "usual routine" this:?

Carry out 'cockpit drill'
Start engine
Depress clutch pedal
Engage gear
Apply some gas
Raise clutch pedal to biting point
Check mirrors and blind spot
If safe, signal if necessary
Raise clutch pedal to move off

At what point did the car "shoot off"?

[Rolebama]

To be honest I've never heard of a petrol car doing this. I have experienced it twice on diesels when governors have failed, but ob neither occasion would I agree I lost control because of it.
Maybe try a Renault Forum?

[Drivingforfun]

I've heard of autos doing this very very rarely, before "drive by wire" and they'd get stuck on wide open throttle or something

I think there was a guy on the news recently who was stuck at ~30mph I think, and the police came alongside and suggested chucking his keys out of the window to see if the engine cut out (silly but they didn't have hindsight on their side), eventually I think they used their car to bring him to a controlled stop

Hindsight again I know but I think if it ever happened to me I'd try the brake pedal and handbrake, worry about the mechanical sympathy later. It's clearly something that there's probably been no reason to test, but would the brakes of an average car be enough to counteract its acceleration? Put simply if you floored the accelerator and the brakes, which force would "win"?

[June1]

@Beelzebub
Yes thanks ..that looks pretty much like a basic moving away manoeuvre I would have used. The whole thing happened in seconds. Somehow after raising the clutch and releasing the handbrake the car accelerated suddenly and shot across the road. I know it sounds incredulous and I’m still trying to work it out myself.

I think it was the unexpected suddenness and the speed of it that didn’t give me time to steer the car clear of those parked opposite.

I’ll have a look for a Renault Forum
Thanks

[June1]

@Drivingforfun
thanks .. I have heard similar stories since looking into this. I’ve been told that putting the car into neutral will slow it down? I hope I never have to put it to the test.. once has been enough!

[olduser]

The Cleo has computer positioned throttle, that is when the driver move the accelerator pedal the position of the pedal is turned into a signal and passed to the engine computer, this converts this signal into throttle position, and sends a signal to the throttle, causing it to move (open).
In turn the position of the throttle is fed back to the computer, the computer decides when to stops the movement, holding the throttle in that position until the driver moves the accelerator again.
If the car is turned off with the throttle open, a return spring closes it.

For the computer to be able to do this, it must know where the throttle closed position is, and throttle full open is.
There are stops in the throttle body.
The computer learns these positions during programming, for this to happen the engine has to be not running but turned on for 30 secs, the computer then drives the throttle fully closed and fully open storing the positional information.

What this lot boils down to is, like many cars today the driver doe's not have direct control over the actual throttle.
The electronics on the accelerator could be faulty, or the electronics driving the throttle could be faulty, there will be instructions in the computer software telling it what to do in these fault conditions.
Or a bug in the software let the computer open the throttle without being instructed to do so.

There may be a fault recorded in the engine computer which would support your case but don't open a bottle of plonk until a expert investigator has looked.

When people say computer software is bug free, what the really mean is they haven't found the next one yet!

As to putting the car into neutral, with engine at or near full power I would take some effort to shift the gear leaver on a manual gearbox, it would stop further acceleration but the car would then be freewheeling !

Using the foot brake, I would expect, would overcome the engine and stall it but a car leaping forward unexpectedly, is not conducive to logical thought, next time perhaps!

Good Luck.

[Rolebama]

I can't remember the circumstances why, but I had cause to drive a car, (on a private road alongside a runway), with foot hard on the brakes and accelerator pedal. The e
engine won, as not having any servo assist, and I was putting all the effort into braking, I was travelling at around 30mph in first gear. However, when I lifted off the throttle and servo got vacuum, the car stopped dead.

We had a few autos before computer contro;s, which would run at higher 'tickover' when cold-starting. It was not unheard of for people to select drive and find themselves taken unaware when the car moved off. Generally, these were people who used Park instead of the handbrake.

[Jo44]

@June1. I have had similar happen to me 3 days ago but I was driving down the bypass pass at 60mph in my hyundai xi35 2013 deisel automatic and suddenly my car started too speed up I pressed the brake lightly but it carried on speeding up so I pressed harder and it started slowing down pulled to verge and car started smoking hour later police arrived as wasnt in a safe spot they tried to move my car and it did the same too them car is now in garage but scared of what's to come of it

[olduser]

It sounds like a fuelling fault (injecting more fuel than needed).
Possibly fuel rail pressure regulator but it is impossible to figure it out remotely.

The garage will be able to run pressure tests and look for any error codes in the cars computer.