serious incident electronic engine malfunction

[rowen16]

hello, i am new to this forum and i would never normally be prompted to ever request help or advice as quite frankly i thought i knew it all. i owned (past tense - now written off) an e200 elegance april 97 auto - which i had driven for nearly 70,000 miles without so much as a blip, and before owned two e class autos -total mileage 137,000 miles.approx 5.30am thursday - switched on the ignition - wanted to warm the car up - before carrying on with my journey, so had no seat belt on - the engine went to 4000 revs but i thought that by putting the car into drive it would be like a manual thus the revs would drop and baring in mind my foot was on the brake - and the hand brake was on - the car would be ok. i thought wrong! the car shot forward and out of control with me wrestling the car with both hands to avoid hitting parked cars and brick walls whilst at the same time speeding up to approx 40 miles an hour (this is in an open car park - in addition i was stamping on the brake with all my weight but eventually the car won and i ended driving into a tree - but by some miracle i didn't go through the windsreen - more worryingly the air bags didn't go off. i now have a badly bruised thumb and whiplash - but i am alive. can anybody share light on this potentially lethal fault, as subsequently the vehicle has been restarted and behaved fine - i am now genuinely quite scared of driving any automatic car ever again - this type of incident did used to happen to old fords but does anyone know of this happening to mercedes benz cars as i'm sure the company itself would never acknowledge this fault but unfortunately they are the only ones who have the equipment to test the car thoroughly to find out what was wrong
please help - thankyou

 

[davidsl500]

Can you clarify - are you saying that you started the car and it revved to and held at 4000rpm on its own ?

 

[jberks]

Glad to hear you're basically ok, it could have been quite nasty, especially if it happened around people. To be fair, the lesson you have learned is to never put a revving auto into drive as without the clutch pedal its an off-on scenario. It could have been caused by a sticking throttle actuator or several other things. The car has a rev limiter at 4000rpm in neutral so if the throttle was stuck full on that's as far as it goes .... until you put it in drive when it assumes you've floored it.

We can all say clever things like why didn't you push it straight back into N or turn the key off but I know from experience, its sometimes hard to come up with the obvious when all hell breaks loose and you're desparately trying to figure out why. I had a steering wheel jam once, I just sat there pushing it left as it drifted right across the road (fortunatly nothing coming) and then realised that if I'd shaken it, it would have cleared, but terror is paralysing.

Rear brakes are much weaker than front ones so on a rwd they will not be enough to overpower the engine, hence standing on the pedal didn't help.

I stop short of blaming MB, a stuck throttle can happen to anything and its certainly not a common fault I've heard of. If it were, with all the US motors and class action lawsuits (remember Ford and Goodyear) , MB would have put out a recall many years ago.

 

[rowen16]

thankyou for both of those replies but to clarify yes when started it revved to 4000 and held all by itself

 

[littlebrooklyn]

There was an article in the newspapers a few weeks ago about a japanese car that twice started itself and drove into a brick wall or hedge, causing a lot of damage. It turned out it was due to a wiring fault, bit scary though

 

[Rory]

Hmm..notwithstanding ABS, I would have expected to see some disturbance of the grass as the tyres were braked heavily.

The airbag won't go off unless the car calculates that it needs to.

 

[Blobcat]

Hi,

Glad to hear you made it out ok and sorry to see the accident.
Airbags did not fire due to position of the impact. People expect them to fire in almost all types of collision when they are actualy set to fire in only
certain conditions. And to the car this one didn't count.
At this time of year it is very common for accidents in auto's especially reversing. Due to the cold start cycle the engine rev's are higher than normal and so when the car is put into reverse (or drive) it has a tendancy to take off. If you can get your head around left foot braking then it is worth learning.

 

[television]

I read the thread last night, sad that the car has gone, but no one hurt.
In all fairness, if one starts the car and the engine runs near max, you know that it is not right, , in my veiw no attempt should have been made to put it in gear.
At least we all know now what happens.
No way can you blame MB.

Malcolm

 

[mioba]

thats really scary, glad to hear you are OK
On my W124 last year i had a similar problem, on turning the car on the revs were at 3.5K
Anyway a good mate of mine is a mechanic at MB and he does my car for me at home, so I called him up.
He asked has anything happened - I told him I was having a battery problem and whilst attempting to charge it i stupidly sparked it - he called me an idiot.
He also said in sparking it you lose some battery power so in revving high the car was compensating for that loss by trying to charge the battery.

He just reset the gearbox - all he done was pull some special fuse (or chip) from under the bonnet and hey presto the revs were fine, he said driving may be a bit different as the car will need to re - learn your driving style.

so did you have any battery problem before this?

hope this info is useful for anyone else here!

 

[television]

He asked has anything happened - I told him I was having a battery problem and whilst attempting to charge it i stupidly sparked it - he called me an idiot.
He also said in sparking it you lose some battery power so in revving high the car was compensating for that loss by trying to charge the battery.


hope this info is useful for anyone else here!

Sorry that is totally incorrect, the charging rate has nothing to do with engine.the car does not try and charge the battery.

malcolm

 

[jberks]

Absolutely, plus, sparking the terminals momentarily will not discharge a car battery by any significant amount. Its actually quite difficult to reconect the terminals without creating a small spark as there is always a small current draw, even with everything turned off. The effect of the car trying to charge a flat battery would actually be to reduce revs as this would load the alternator and so load the engine and pull the revs down.
Also the re-learning on the gearbox will happen in seconds. The changes in modes are pretty small in reality and change constantly as you drive anyway.

 

[philharve]

Hi All

I've just finished replying to 'benz400' who also reported a revving engine culminating in an accident and resulting in striking a tree.

Coincidence?

REGARDS Phil

 

[jberks]

Seems to be a spate of them. Just heard the most rediculous thing on the radio, Bloke in in a Beemer, throttle jammed. Ok so far, as we've seen, these things happen. Ok, you may panick for a few secs, but this one drove for 60 miles at over 100!!
Burned his brakes out trying to stop.

Has no one heard of the ignition key?

 

[Blobcat]

Seems to be a spate of them. Just heard the most rediculous thing on the radio, Bloke in in a Beemer, throttle jammed. Ok so far, as we've seen, these things happen. Ok, you may panick for a few secs, but this one drove for 60 miles at over 100!!
Burned his brakes out trying to stop.

Has no one heard of the ignition key?

One of my customers used to have quite a large fleet of Diesel Maestro's as these vehicles were treated rather hard a number of them had their sumps damaged. What happened to four of them is that the breather became squashed and the engine then ran on its owm sump oil. Switching the ignition off made no difference. The engines stayed at full revs until they ran out of oil and seized. Thankfully no one was huirt as all the drivers stuck them in neutral.

 

[philharve]

One of my customers used to have quite a large fleet of Diesel Maestro's as these vehicles were treated rather hard a number of them had their sumps damaged. What happened to four of them is that the breather became squashed and the engine then ran on its owm sump oil. Switching the ignition off made no difference. The engines stayed at full revs until they ran out of oil and seized. Thankfully no one was huirt as all the drivers stuck them in neutral.

Hi Blobcat

So, turning off the ignition in certain circumstances doesn't shut down a revving engine. That news to me.

REGARDS Phil

 

[philharve]

Seems to be a spate of them. Just heard the most rediculous thing on the radio, Bloke in in a Beemer, throttle jammed. Ok so far, as we've seen, these things happen. Ok, you may panick for a few secs, but this one drove for 60 miles at over 100!!
Burned his brakes out trying to stop.

Has no one heard of the ignition key?

Hi jberks

I read this news item too and used it in another thread as an example. I thought of the 'ignition switch' too. It's the obvious solution.

But then a thought occured to me. With the complex security system and ignition system in a modern Mercedes controlled by the ignition switch, I assume rotating the ignition key anticlockwise 'one click' will kill the engine whilst the car's in motion? But is it possible to fully rotate the key and withdraw it in the same circumstances without engaging the steering lock?

Killing the engine whilst the car is in motion is a sensible safety precaution which the BMW owner should have realized. But do you know whether its possible to withdraw the key altogether, either by accident or by intention, whilst the car is being driven. I assume interlocks will prevent this from happening so the car can still be steered with the engine off? I've never tried this myself, nor would care to. I assume BMWs are no different to Mercedes in this respect?

I read this 'BMW story' in several newspapers and each with slightly different variations in detail. However, I find it unbelievable anyone could drive through three Yorkshire counties at speeds well over a hundred with the police in hot pursuit and a helicopter above, and no one suggested to the driver to switch off his ignition OR put his car into neutral.

In one newspaper it was reported he felt he had some control because he managed to hold his car at around 70mph by keeping his foot brake depressed. Now I ask you, is this the action of a driver with a full bag of marbles?

Unless there is a watertight technical reason why he could do neither of the above, he should be prosecuted for endangering other road users.

REGARDS Phil

 

[Blobcat]

Hi Blobcat

So, turning off the ignition in certain circumstances doesn't shut down a revving engine. That news to me.

REGARDS Phil

Only on Diesels as they do not require a spark plug to ignite the fuel. Once a diesel is running it is the compression which causes the fuel to ignite. However with diesels switching off the ignition will switch off the fuel pump so the engine should switch off. The problem with the Maestro's in question is that they started to use their engine oil for fuel so switching off the fuel pump made no difference.

 

[LNM]

I'm assuming the car was in N when you started it ?

If not, what happened when you shifted it out of P to get to D via R and N respectively ?

 

[Seeker_UK]

Only on Diesels as they do not require a spark plug to ignite the fuel. Once a diesel is running it is the compression which causes the fuel to ignite. However with diesels switching off the ignition will switch off the fuel pump so the engine should switch off. The problem with the Maestro's in question is that they started to use their engine oil for fuel so switching off the fuel pump made no difference.

An ex g/f of mine had a really old Moggie Minor and she ran it w/out any water in the radiator! When she stopped the car, the heat in the pots was enough to cause continued combustion of the fuel even when she turned off the ignition.

Obviously though in a modern car, if this happened the head would cook and the car would sieze alot quicker....

 

[LNM]

Spooky, I had a 1988 Nissan Blueburst that would (albeit randomly) do the same; but it had all its water.