Sticking Accelerator/Runaway Car.. Have you had one?

[psmart]

A suggestion was made to start a thread specifically to deal with Accelerators/Throttles which have stuck, or engines which have gone AWOL causing a runaway vehicle.

Have you had such an experience? If so, please add your car type and experience to this thread so that we can find out how widespread this phenomenon is and possible solutions.

Hopefully a kind moderator will make this thread sticky for a while to get useful feedback.

Point of reference thread: http://forums.mercedesclub.org.uk/showthread.php?t=18537

 

[Blobcat]

You should have made it with voting buttons

 

[MW]

Happened on an old Talbot Solara of mine many years ago. I just switched of the engine and the vacumn in the engine then seemed to suck the carb, and the thottle went back to normal. It is frightening at first, but not the end of the world. Don't panic and be logical. Switch of the engine but keep the key in for the steering lock.
All solved in the end with a new cable, which was twice as smooth and easy. You get very use to a progressively stickier cable.

 

[philharve]

A similar experience reportedly befell a driver of another marque (BMW) a few months ago and resulted in a high speed inter-county dash that ended in a crash but no serious injury. The incident was widely reported in the national newspapers. Don't know what happened to the driver who said he couldn't stop the car.

Sticking accelerators do happen and I experienced something similar in another car, not my Mercedes. It was the accelerator cable itself that got stuck inside its sheath. There were warning symptoms but I foolishly ignored them. When the incident happened it was easy to control and did no damage. I stopped safely by switching off the ignition.

I understand modern Mercedes don't use accelerator cables; they use a fly-by-wire system comprising a potentiometer and an electronic linkage.

I would have thought a 'stuck accelerator' is a very rare event unless it involves an older Mercedes, solid cable linkages and carburettor controls.

REGARDS Phil

 

[Parrot of Doom]

The above incident was total bollocks IIRC, the car was faultless.

 

[Myros]

one of the missus's company cars, a Vectra ( spit)

tried to kill me. I had borrowed it to do an errand, and driving back, it started speeding up. I fought it manfully with the brakes, and had to switch off at lights and halts, jam it into first , restart and drag the clutch with the brakes hard on to keep the revs down. I told the mechanic at the dealers what to do to drive it in safely, but he thought he knew better. I very nearly didn't laugh as he rocketed across their car park. They eventually asked me to manoevre it into the bays for them. I never trusted the thing again after that and was glad when it was gone, an unusual sentiment from me.

 

[television]

I understand modern Mercedes don't use accelerator cables; they use a fly-by-wire system comprising a potentiometer and an electronic linkage.

I would have thought a 'stuck accelerator' is a very rare event unless it involves an older Mercedes, solid cable linkages and carburettor controls.

REGARDS Phil

Almost every thing now uses fly by wire now, its partly down to cost, electronics are cheap for the manufacture, compaired to the engineering of a buttefly ass;

Malcolm

 

[psmart]

Fly by wire....

..... Modern Mercs may look like they use the old mechanical cable for throttle, but all is not as it seems. Photos of the Potentiometer, mounted on the bulkhead in engine bay, but fed by sleeved cable...

Your not in charge, the computer is (ECU).....

 

[philharve]

..... Modern Mercs may look like they use the old mechanical cable for throttle, but all is not as it seems. Photos of the Potentiometer, mounted on the bulkhead in engine bay, but fed by sleeved cable...

Your not in charge, the computer is (ECU).....

Hi psmart

So the accelerator pedal operates a potentiometer in the engine bay via a short cable? Is that how it works? I thought the potentiometer was mounted near the pedal and directly operated by it? Maybe there are different accelerator arrangements for different Mercedes?

When I experienced the 'runaway car' problem many years ago, it was the lack of lubrication (probably) of the accelerator cable that eventually caused one of its strands to break and snag in the sheath. Replacing and relubricating the cable was easy. Problem never recurred again. Could have had serious consequences though.

REGARDS Phil

 

[SomethingRattling]

Cable linkage........ Fly by wire........ Why not bluetooth linkage! at least if the accelerator pedal fails could could always associate the engine linkage to your mobile and use the volume up/down to get you home! Oh I forgot, its dangerouse to use your mobile whilst driving.

 

[psmart]

Cable linkage........ Fly by wire........ Why not bluetooth linkage! at least if the accelerator pedal fails could could always associate the engine linkage to your mobile and use the volume up/down to get you home! Oh I forgot, its dangerouse to use your mobile whilst driving.

Are you serious? Wouldnt trust anything based on wireless technology to control sensitive equipment. Bluetooth is a non-too reliable technology, fancy having the Accelerator on your car partnering with an engine ECU on another car.... think of the chaos

So the accelerator pedal operates a potentiometer in the engine bay via a short cable? Is that how it works? I thought the potentiometer was mounted near the pedal and directly operated by it? Maybe there are different accelerator arrangements for different Mercedes?

Could be on newer cars, example is MY2001. It may just be that certain engine possibilities for the ML may have had mechanical injection/carburation, but I doubt it. May just be a mechanical engineers slow progression to putting the potentiometer at the foot pedal. This mechanism (on the ML) gives a very bad 'jerk' acceleration when stuck in traffic jams, which oigle has a good thread on to fix: http://forums.mercedesclub.org.uk/showthread.php?t=15521

 

[television]

http://forums.mercedesclub.org.uk/attachment.php?attachmentid=1438&d=1149316766.

You can see the throtle pot here on my 129 that sits on the front wing, ignore the swith on the left that's for something that's coming later

Malcolm

 

[bobcr]

I have this problem on a c270 cdi auto estate 2002
Not had the car that long when I overtook a car and floored the throttle pedal, when I passed the car and took y foot off it just kept going at full tilt, frightened the life out of me ! I had to kick down hard on the throttle until it came off luckily. Then tried it a few more times om an empty road and it happens every time the throttle is floored. I hadnt experienced it up to then as never had to floor the pedal before.
Is the throttle on this car a fly by wire type ? Does it have a short cable then some kind of potentiometer ? How easy would it be to take out the pedal and cable if there is one ?
Any advice appreciated, just glad my wife wasnt driving at the time as she is the panicky sort and this is potentially a fatal problem !
Bob

 

[teddycatkin]

Almost every thing now uses fly by wire now, its partly down to cost, electronics are cheap for the manufacture, compaired to the engineering of a buttefly ass;

Malcolm

Leave sex out of this please Malcolm?:lol:

 

[denisb847]

clk 200k 2003 car went to full throttle when breaking.

I just had a close call/ near serious accident,I was slowing down from 80k to 50k and noticed my car was not stopping as I braked to stop.I had to use a lot of force to stop my car,when I came to a halt I sensed the car was straining to move,I shifted to neutral and the engine went to full throttle,I then switched off the engine,when I started the engine again it was still revving at full tilt,I again switched off the engine and restarted and the same was happening,I was beginning to get panicked all I could do is switch off again and leave it off until the traffic in front started to move and try it then ,as luck or whatever would have it the car behaved normally,I drove home very carefully making sure not to be too to the cars in front of me.this is a very serious fault for a car exhibit and could have been fatal.I am also worried that the gear box my be weakened because I shifted between drive and park and the car rocked slightly as I did this, any comments ???.denisb847

 

[Naraic]

You will have to get it to your mechanic and have the codes read.

 

[ric220]

I had a throttle stick on max years ago on my 1978 w116 350se on leytonstone high rd, east London. Turns out the floor had rotten through and putting the "pedal to the metal" actually meant "pedal to the tarmac". Needed both feet on the brake to end an entertaining few mins of Merc ownership...

 

[Rappey69]

A friend had a daimler double 6 .. 5.3 litre ??
Wanted to have a go to see what it was like..
got in, drove along the road and had permission to "floor it" , so I did.
It flew up to 80 and decided that was way to fast for where i was so let go of the accelerator...
omfg, no responce and still accelerating like a scolded cat...
Instantly turned off the ignition whilst braking for England..
Stopped the car, got out and was happy to have escaped without incident..
Turns out the footwell mat has a fairly solid back and it had crept up the accelerator pedal so when i planted my foot down the mat then held the pedal to the floor !!!
I think my friend had heart attack !!!

 

[toby1]

It's never happened to me

 

[Naraic]

I did the same in an Alfa 33, the throttle was jammed by the mat...oops.