I was in town earlier and saw some woman revving the **** of her citroen xantia diesel or so I thought, until she got out of the car looking very worried with the keys in her hand the car kept on revving until there was a loud bang and then proceded to dump a large amount of oil all over the floor. shouldnt laugh but

How the heck can this happen? surely once the ignition is cut the fuel pump will stop

 

Thought Diesel engines had some sort of guvenor to stop them overrevving/doing this, maybe it failed.

Rememeber the farm-boys on Scrapheap challenge removed the guvenor from a whopping big truck Diesel and it went into meltdown.

A real bloke would have dumped it into 5th and stalled it to a stop

 

could be a citroen petrol running on / pre-ignition ? They're rough enough to sound like a diesel

 

I just watched the carnage unfold def a diesel, left an impressive smoke cloud when she blew.

I remember when the con rod came through the block on my old mondeo, the whole cabin filled up with smoke and I was doing 60mph at the time

 

Actually, I picked up a Citroen ZX TD which did the same after the turbo went on the M60 - while it was on the way to the scrapper!

Did exactly the same thing.

 

once the rings go and it starts using oil from sump as fuel the only way to stop it is stall it really.

 

its the turbo oil seal gone, basically lets the engine run on sump oil and because the governing is done through limiting the fuel supply then they basically cannot be switched off. we had it in a Laguna and because of where it was parked couldn't stall it. Bloody scary and creates a serious amount of smoke. Only way roung it we found out later is to stall in 5th, our one ran for about 5 mins before it ran out of oil. Its a known problem hence renault put a new engine in FOC

ours resulted in police and firebrigade being called by other people and some nice helpfull biddies saying why don't you switch it off

 

I was thinking to myself,switch the engine off you daft bint Wish I had recorded it now

 

its definitely impressive we had a load of people going to church to a christening who had to go through the smoke and that was about 200 yards down the road

 

the isuzu 3.0l is a good one for that, at the minute if you have one that goes bang due to an injector fault (fills the sump with diesel) isuzu replace it free of charge regardless of age or mileage.

 

Thats something useful to know

 

Yup self destructing diesel:

2.2 Dci Lagunas are known for it, had to drive one back when the turbo seals had failed. Fine off boost, but as soon as teh turbo spun up...whoa nelly!

Basically any failure, be it rings, holed piston, turbo failure...or just simply overfilling the engine with oil will cause the engine to run off its own oil.

Once thats happened, all you can do is put it in 5th gear stamp on the brake pedal hard and jump off the clutch....that may save your engine.

 

sounds exactly like what happened to me when i had that turbo diesel 07 passat as a courtesy car while the scoob was being accident repaired...

if you dribbled it slowly it was fine. any sort of accelrator pressure and it was bouncing off the rev limiter and spunking black **** everywhere from the exhaust. thought it was the turbo.

 

seen it before when i worked at a pug dealer,turbo shaft sheared pumping sump oil in to inlet.
this resulted in engine revving like fu3k and finally stopping when all oil had gone and no4 rod came out of rear of block

 

Shame it doesn't happen to all diesels.

 

Whys that?

 

Worn engines run on their own oil (because they arent running on fuel oil the engine speed cant be controlled): as they over rev the blow-by increases as do the revs until they go bang! The only way to stop them is to dump the clutch in 5th gear with your foot on the brake.

Simon

 

Correct, Its fairly common with the 1.9 turbo diesel in the Laguna, Thoughts are that its the EGR valve clogging with carbon that causes the turbo to run Extra hot and destroying the oil seals. This has been going on for the last 3 or 4 years and still Renault will not accept there is a fault, although they will contribute towards costs for a new turbo.

 

With respect to Lagunas, they do have issues where the oil return from the turbo blocks up. The result of which is the turbo blows its seals.

A laguna engine that suffered this fate (on its 2nd turbo- also with blown seals due to the blocked return) also burnt a hole through its pistons because of incorrect combustion. caused by it burning engine oil.

Thankfully; because it wasn't allowed to self destruct, it was rebuildable, so stalling the engine in 5th/6th saved the owner a fair few bob.

 

It was also Renault that had the issue with hot handbrakes. You would park up on a slope, use the handbrake and the car would hold (without being in gear). As the brakes cooled, the pressure from the handbrake weakened and the car rolled off down the hill.

They ended up having to show it on Watchdog before Renault admitted there was something wrong. The handbrake held the car for 20 mins on Watchdog before it rolled off

 

I thought that was Citreon. Especially the Xantia and XM: the handbrake works the front brakes, which obviously got alot hotter than the rears during normal use. Discs expand with heat, contract when cool: Result is a load of Xantias rolling down hills after half an hour

 

NEVER EVER buy a french car with your own money.....:nods:

 

PMSL!

Reminds me of a guy I knew who had a 1.4 petrol Astra, for some reason this developed a fault whereby taking the ignition key out the engine would not stop running. My reply was "so what did you do?" and he said "I have a lump hammer with me and open the hood up and keep belting the engine until it stops" Laughing as I type this as it's so stupid

 

Seen many a Laguna with this exact problem, the smoke generated is horrific.

Most dont realise they can stall the engine they just jump out key card in hand wondering what f#ck is happening with other motorists saying 'why dont you turn it off'.

 

As a young teenager I worked on a farm in the summer. We had an old Ford Dexta tractor which had a faulty governor. We were trying to sort this in the workshop one afternoon when the engine started to rev to buggery

The exhaust silencer blew off and disappeared through the asbestos roof. We and my mate legged it out of the shed. The farmer turned off the fuel **** and ran too.................

It stopped a few minutes later, in one piece. It took a couple of hours for the exhaust fumes to die down

 

Once the oil control rings go on a Diesel your screwed, it will run off the engine oil until its consumed it all.. then sieze up and spill its guts

 

Is it wrong I want to see this happen?!

 

I suppose with an automatic youd shove it into park and leave

 

No, I was thinking the same thing.

 

Your screwed, as you can't stall an auto.

Only hope is to shove rags up the air inlet (preferbly wet) and a up the exhaust (if you can find it in the smoke ).

Run away diesel are quite fun; as people tend to run in all directions when one starts revving its head off.