Coming back down the m62 yesterday after been to east coast Bridlington i could see in the distance smoke over the motorway and the third lane was clear to a point, cars braking and hazzards on as they slowed down.
As i approached a renault Laguna estate was at full revs with driver out of car on hard shoulder on phone and smoke gushing out of tail pipe, a nice white colour.!!
Didn't stick about needed a pee so off at next junction i guess it blew up eventually as the oil ran out.!!
Do you know the problem?
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I've seen a diesel transit do the same, the only way to stop a diesel that's gone 'open loop' is to cut off the air supply. Usually due to a knackered piston ring or whatever allowing the engine to use it's own oil as a fuel supply I think.
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>> eating its own whatsits
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Ah right, cheers; oil seal on turbo goes and so engine uses lubricating oil as fuel that way then.
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Ah right, cheers; oil seal on turbo goes and so engine uses lubricating oil as fuel that way then
Thats it it goes bang when oil is empty.
You can stall the engine but also risk damage to clutch gearbox which maybe cheaper.
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no damage to clutch or gearbox, they are easy to stop, if only anyone had the brains to do it.
Its not just a renault thing, all turbo diesels can suffer from it. Pleny of clips on youtube of it happening to BMWs,
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>> Plenty of clips on youtube of it happening
Just search for "diesel consuming engine oil" or similar. Our warehouse guy had it happen to his Rover 45 diesel - 7000rpm and no way to stop it until it seized.
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Makes one wonder whether it would be useful to have a block of something pre cut to air intake size in a holder under the bonnet or a home made choke flap linked by cable to the cabin that blocked it.
I saw a fellow standing by his Disco revving itself to destruction, really felt for the chap.
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When I'm working on a diesel engine, I keep a full CO2 fire extinguisher handy for when I start it up again.
Diesel engines which are to be used where there is a danger of a flammable atmosphere are fitted with a device to block the inlet manifold in case of over-revvving.
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>> When I'm working on a diesel engine, I keep a full CO2 fire extinguisher handy
>> for when I start it up again.
Would firing said C02 extinguisher down the air intake stop a runaway NC?
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>> Would firing said C02 extinguisher down the air intake stop a runaway NC?
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I hope so!
I had a couple of problems with cars years ago, but since I have been keeping a CO2 extinguisher nearby, I haven't had cause to put it to the test.
One was a Nissan Bluebird where the governor drive failed in the injector pump while I was giving the engine a good revving after fitting a cam belt.
Another was an Astra diesel which would run away if you revved the engine a bit - the car came in because the customer reported the car was lagging and keeping pulling even after releasing the throttle. So, with the car on the ramp, I gave it a bit of a rev! Thankfully, it stopped when I switched the key off!
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A colleague's Vectra CDTi did it this week, for the second time in 65000 miles. The first time, he saved the engine by stalling it. This time it's toast, apparently.
I've heard of it happening on many makes of car. It must be quite a frightening experience.
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Does it happen only on turbodiesels? Or could it happen to a petrol turbo as well?
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>> Does it happen only on turbodiesels? Or could it happen to a petrol turbo as
>> well?
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Couple of differences - no spark plugs in a diesel so it can't be killed by turning of the ignition, and it's engine oil that's burning and that can't happen in a petrol engine.
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>> Does it happen only on turbodiesels? Or could it happen to a petrol turbo as
>> well?
>>
It doesn't need to be a turbo diesel - normaly aspirated diesels will happily run on their oil too. Excessive piston / bore wear is the usual cause on naturally aspirated engines.
Usually petrol engines stop when you turn the ignition off and stop the spark and fuel injection. They won't rev uncontrollably, as there's a closed throttle valve. However, petrol engines with simple carburettors can run on if there's a hot spot, or some hot carbon in the combustion chamber. Many carburettors made during the 80's and early 90's had some form of electrically controlled fuel cut off to prevent run on.
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>> However, petrol engines with simple carburettors can run on if there's a hot spot, or some hot carbon in the combustion chamber. Many carburettors made during the 80's and early 90's had some form of electrically controlled fuel cut off to prevent run on.
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When I worked for a local authority back in the early eighties we had a fleet of Marina vans and running on was quite a common feature, anything up to half a minute on the worst culprits.
Mind you, that was small beer compared to some of their other "features".
Last edited by: Robin Regal on Mon 25 Apr 11 at 11:06
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When I worked for a local authority back in the early eighties we had a fleet of Marina vans and running on was quite a common feature, anything up to half a minute on the worst culprits.
>>>>>
>>>>>>>.i can remember them doing that but it was because they were extra tweeked to get the best economy out of them,if you ever took any plugs out and looked they were always bright white
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>> As i approached a renault Laguna estate was at full revs with driver out of
>> car on hard shoulder on phone and smoke gushing out of tail pipe, a nice
>> white colour.!!
Getting more and more common.
DPF engines are especially prone, as, as has been previously noted, the oil level in such engines often rises, due to failed purges, and if allowed to rise too far, will act as fuel.
Whilst it may be possible to stall some cars, most drivers will panic and run from the car... and if the car is a auto, how would you stall that??
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ISTR that is a very specific problem on Mazda 6 diesels due to failed regeneration of DFP. Huge thread on the subject back on the dark side.
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If you jknow where the air intake side of the air filter is, a runaway diesel can be stopped in 5 seconds. Place a towel/book/sock/thick newspaper over the intake. No air = no go.
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I know someone who tried that with thick, paper towel.
They 'think' it all came out the exhaust.
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It takes a brave soul to get within a foot or less of an engine screaming out of control, way beyond its design rev range, and with a rapidly diminishing reserve of lubricating oil. When the internals inevitably decide to become externals, leaning over the thing is the last place you'd want to be.
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>> ISTR that is a very specific problem on Mazda 6 diesels due to failed regeneration
>> of DFP. Huge thread on the subject back on the dark side.
>>
If only.... Mazda 5's also suffer badly from this - in fact when I worked for Mazda there were more 5's than 6's suffering with the issue.
Also, the Manufacturer I currently work for, released a bulletin last week, warning on an impending recall for 'diluted engine oil issues'
I can't say which cars they are because its not yet in the public domain BUT it most certainly is not Mazda, when it becomes public people will be surprised.....
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This used to happen to Mk 1 Golf Diesels my dad's company used to run (no turbos in them days). Stalling them was the answer.
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Renault laguna estate going bang.!! - spamcan61
