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Turn off the key, and the air intake flap will close and the engine will stop on most post mid-90s diesels.
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If it`s up to 7,000 revs though and sucking air in like a jet engine - won`t it just take the flap straight down the intake?
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won`t it just take the flap straight down the intake?
Probably.
But would that really matter? the engine is scrap by that point anyway.
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The engine speed won't make much difference - there's a fairly hard limit on the pressure difference across the valve, and as air doesn'r weigh much, there isn't much extra stress from water hammer types of effect.
I would use a CO2 fire extinguisher to stop a runaway diesel - I tend to keep one handy when I'm starting an engine I've just worked on - and for those engines (rare nowadays) where you set the valves while it's running.
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"Shove it into first gear and then take the key out of the ignition with it on full lock - then leap out . ;-)"
don't you mean fourth gear and bang the clutch out !
Probably wouldn't stop the engine anyways. he he
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Frequently caused by failure of hoses between air cleaner and inlet manifold or blocked air cleaner.Engine then tries to get all it's air thro' the crankcase ventilation system and sucks up engine oil with it.Swithching off won't have the slightest effect-it's not running on diesel and it's getting what air it can out of the sump.
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I saw the happen yesterday on the M6 heading south past Preseton. Just as you come down the hill there was visible smoke in the foreground. Then everyone slowed.
As I passed the cause (near zero visibility the smoke so thick) could see it was a Galaxy on the hard shoulder with smoke coming out from underneath, with by then a policeman in the drivers' seat.
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Doesn't a petrol engine with a tank of diesel produce a similar effect....
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I still do not know why Galaxy/Sharan I saw produced that smoke - cannot be sure if it was a Galaxy or Sharan let alone model. You could see no more than one foot ahead and caught a glimse as I passed and looked to the left.
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if its a laguna
be sure you have fully comp with a minimum excess and protected no claims
and let it blow
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Well, i thought about stalling the engine, seems obvious, but a turbo diesel revving itself hard at say 3 to 5000rpm would take some stopping.
I'd have thought the engine would overpower the clutch at standstill quite easily.
So one for the brave, drive car for short distance if possible, get into as high a gear as possible at as slow speed as possible without the clutch slipping and then force it to standstill on the brakes.
As i said before this would take some nerve, not sure many of us would try it.
Secondly, and this is assuming the turbo seals have gone allowing this to happen, if getatable would smashing the turbo oil pipe stop the 'fuel' supply.
I'm trying for example to work out how we'd stop the hilux auto diesel if this happened.
The air intake seems to be hidden and almost inaccessible, so bunging that up isn't likely.
This is all very well from the comfort of our homes, a lot different for the poor chap thismorning vanishing into a hellish fog whilst no doubt hearing his engine attain revolutions he never thought possible, and maybe even assumed the car itself was on fire.
Strange people like us here in the BR may have an idea whats happening, but i would suspect 99% of drivers wouldn't imagine such a thing could ever happen.
Edit...unless anyone else has any brilliant and safe thoughts NC's fire extinguisher seems probably the safest...assuming the air intake can be got to.
Edited by gordonbennet on 04/06/2009 at 21:49
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i still think its best letting it blow if you are fully comp
you could die from shrapnell wounds
i once lifted a bonnet as the engine was on fire,i wont do that again
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you could die from shrapnell wounds
Thats exactly what i mean BB, all very well theorising, but the noise smoke and mayhem would all but terrify most and definately me..;)
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Engage the highest gear e.g. 5th or 6th with right foot firmly on brake pedal and let clutch up gently?
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I think too gently it would overheat pretty quickly but would too fast rip a DMF to pieces?
Probably is a way of doing it, a bit like proper launch control
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At those kind of revs, would probably burn the clutch out within seconds.
Or worse.... shear the flywheel bolts - nasty.
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Friend of mine had the answer - he collects tractors and Field Marshalls in particular - one day he checked oil and nothing on dip stick so filled it up -started it and it started to rev - he closed throttle but nothing happened so the answer he and his mate had was "run like hell" after which it blew up with cast iron all over the barn - he sourced a new bottom end from Australia. - Very expensive oil fill.
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The clutch should stop an engine running on its oil - despite the speed, the engine can't produce much output torque, because the combustion isn't particularly efficient, and the clutch is always sized to cope with maximum engine torque plus a manufacturer specific margin of safety.
An automatic, however,....
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An automatic however ....
What would happen if you just shoved it in reverse, an exploded gearbox AND a self-destructing engine?
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"don't you mean fourth gear and bang the clutch out !"
No first. Fourth would be too fast to catch the action on my G600...
Edited by oilrag on 04/06/2009 at 22:54
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Would blocking the exhaust have any effect? Perhaps one could insert a suitably large potato?
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I knew that Hondastyle potato in the boot of the CRV was there for a reason !
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you cant even stop a basic car these days with the old potato, the injection system just keeps pumping and all you get is well a very hot potato, or normally a very smelly rag
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>>Would blocking the exhaust have any effect? Perhaps one could insert a suitably large potato?
Throttling the exhaust of an engine is less effective than throttling the inlet in controlling the output power - typically by a ratio which is similar to the compression ratio.
Obviously, completely and effectively blocking either will stop any engine.
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my project for tomorrow nc if you care to take it----- :-)
try stopping a modern car with a potato, an orange, or even a large bandage,the heat generated makes me abort even if i use a cloth on a stick to try and find a leak
i fail before the engine does
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Quite so - it's surprising to see how well an engine can run against a blocked exhaust.
I well remember an older customer of my father's who really should have hung his keys up. He brought in his immaculate Triumph Acclaim with a low power and overheating problem. It caused us quite a bit of head scratching until one of us noticed that you couldn't feel any exhaust pulses at the tailpipe. Once we had picked up on that, the wheezy running of the engine made sense - the old gent had reversed into something which had crushed one of the exhaust silencers.
The sad bit of the story was that a few weeks later, he misjudged the manipulation of the automatic gearlever, and put the car into reverse while doing 30 or so. The resulting large bill was the final straw which stopped him driving any more.
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I think I'm correct in saying that most Diesels do not have a flap in the intake as mentioned stopping the engine, also if you put it into gear and let the clutch out at 5k rpm you'll burn it out before stopping the engine.
No good disconnecting the battery as the alternator will produce power to continue supply.
The only possibly way of stopping the engine maybe would to remove the main fuse in the engine bay or fuse panel for the ignition circuit.
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you'll burn it out before stopping the engine.
No chance.
The clutch copes with slipping from zero to at least tick over speed thousands of times during its life, moving the mass of the whole car. Stopping a quickly moving engine, which can't produce much torque, which has a tiny inertia compared with the car, once isn't a problem.
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No chance. The clutch copes with slipping from zero to at least tick over speed thousands of times during its life moving the mass of the whole car. Stopping a quickly moving engine which can't produce much torque which has a tiny inertia compared with the car once isn't a problem.
Sorry but I beg to differ.
Not all manufacturers have a good strong biting clutch, some I've driven (new) you can and done it, reving the engine to 3 or 4k rpm and letting the clutch go in 5th or 6th gear. They will not stall a Diesel turbo driven engine, even some petrol engines. Mostly the Asian/Japanese and some of the Europeans. Driving these everyday.
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They will not stall a Diesel turbo driven engine
I think under the circumstances being discussed here we are assuming the engine to be running on engine oil it's getting from somewhere it shouldn't.
I wouldn't have thought the engine would be producing even half its normal power this way. The revs may be high, but there may be little power backing them up...hopefully.
I do agree with you about some clutches though, some cars we load have to be driven onto the trucks in a 'determind' manner as the clutches are just not up to the job...though that usually goes hand in hand with a gutless engine that has to revved too much just to get the thing to climb.
In the Youtube clip above (below even), was the X5 a manual and did the chap in the black T shirt stall it as suggested i wonder?
Edited by gordonbennet on 05/06/2009 at 22:02
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i assume you mean without using the brakes at the same time? if you have your right foot on the brake to the floor and your left on the clutch and the handbrake on as hard as you can and dump the clutch in 5th or 6th the engine WILL stall, it's not making the power it should and the car has 1300kg+ of weight to start moving in top gear and all the brakes on hard.
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A diesel in runaway mode is generally fuelling itself independently of the injectors - otherwise the governor would hold the engine (relatively) safely at max speed.
The most common sources of "fuel" for a runaway engine are crankcase oil via the breather system, turbocharger bearing oil via the intake or a spurious input such as LPG in the bottom of a boat hull. There are a few specific cases where a fuel system fault will allow unmetered fuel to be injected but I am not presently aware of any of these being applicable to CR or current production unit injector diesels.
Blocking the air intake is the most certain way to bring an engine to a halt unless large volumes of crankcase air/oil are available to the engine. Normally the small bore of the breather pipes will ensure that insufficient air is available to sustain dangerous engine speeds if the main intake is blocked.
On a vehicle with manual transmission, engaging the clutch smartly in a high gear with the brakes on will stall practically any engine.
659.
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The owner of this X5 clearly wasn't too sure what to do (YouTube link):
tinyurl.com/o6ck2s
It happened to a friend in a Freelander TD4 auto and he reckoned it was terrifying. He walked up the motorway embankment, sat down, lit a cigarette and waited for the bang which came about a minute later.
Engine was removed from the car, stripped of ancillaries, and dumped in a skip. Nothing salvageable whatsoever.
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Wow = I challenge anyone to have stuffed a potato onto that exhaust. Chap in the black tee shirt knew what to do !
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