Curious as to the cause of this epic failure.

Iamzod · 15 Apr 2014 at 01:17

I was out in the car earlier when I see white smoke start pouring from an early 2000's Octavia, the guy pulled over & got out & as I passed a few seconds later it sounded like the car was just bouncing off the rev limiter with nobody on board & smoke pouring out. The smoke quickly turned black shortly after with the car vanishing in its own cloud.

What could cause an engine to destroy itself in this way?

opstrat · 15 Apr 2014 at 01:31

Lack of oil maybe.

OhEsEcks · 15 Apr 2014 at 02:06

Sounds like diesel runaway.

Edit: Better video.

http://en.wikipedia.org/wiki/Diesel_runaway

PaulyD · 15 Apr 2014 at 03:45

OhEsEcks said:
Sounds like diesel runaway.

Edit: Better video.

http://en.wikipedia.org/wiki/Diesel_runaway

Was about to say the same, just read a thread on PH about this very thing earlier

Katoom · 15 Apr 2014 at 05:58

If engine oil gets into the intake side of a diesel, it'll act as a fuel and ignite under the compression.

Minstadave · 15 Apr 2014 at 07:22

Yup they just run until the oil is used up and they seize. Even with the ignition off as the oil will self ignite like diesel.

Tesla · 15 Apr 2014 at 07:37

I saw a 306 do this yesterday too, did wonder what had happened.

kaiowas · 15 Apr 2014 at 07:45

Minstadave said:
Yup they just run until the oil is used up and they seize. Even with the ignition off as the oil will self ignite like diesel.

Presumably if you were alert to what was happening (and it was a manual) you could still deliberately stall it?

TaKeN · 15 Apr 2014 at 07:45

This can also happen if you overfill the engine with oil. It has to be rather over filled though!

A chap who I worked with told me about an engine years ago, where an injector pipe burst, made a hole in the airbox, and proceeded to keep supping the fuel down the air intake :eek:

sovietspybob · 15 Apr 2014 at 07:47

this happened to a guy i work with in a works astra van years ago, as he didn't know what to do it ended up catching fire and burning itself out.

Assuming its a manual best thing to do is stall it in gear with foot on the brakes, otherwise shove a rag up the air intake and starve it of air. Hardly anyone seems to know this however

godinman · 15 Apr 2014 at 07:47

kaiowas said:
Presumably if you were alert to what was happening (and it was a manual) you could still deliberately stall it?

With all them torques? You must be kidding!

bad_ass_neil · 15 Apr 2014 at 08:23

this happened on a scrap heap challenge episode. they put a rag in the intake, looked very scary when you have a massive tractor engine going crazy though.

Muffin` · 15 Apr 2014 at 08:27

sovietspybob said:
Hardly anyone seems to know this however

Trying to find it might be a challenge, you won't have long to do it before there's zero visibility.

wesley · 15 Apr 2014 at 08:32

bledd · 15 Apr 2014 at 08:37

I've seen this happen on the side of a dual carriageway. Car was on fire and thick black smoke bellowing out of the exhaust.

The two guys that were previously in the car were only stood about 10 feet from it. Judging by the noise it was making, I would have been 100 foot away if I was them!

Dale V · 15 Apr 2014 at 08:51

I've done this before to a Focus, but I managed to stop it by stalling.

Rybo89 · 15 Apr 2014 at 08:53

It's gunna explode! Yep 95% people would panic and go into spaz mode.

I have never seen this. Can new oil burner cars do this?

DaveyD · 15 Apr 2014 at 09:34

It's definitely still possible on new modern engines, I've seen it happen.

Generally newer engines are designed to try to reduce run-away oil burning, but it still can happen in the right(wrong) circumstances.

OhEsEcks · 15 Apr 2014 at 09:48

Rybo89 said:
I have never seen this. Can new oil burner cars do this?

It can happen to pretty much any diesel motor. Piston rings leaking. Turbo seal leaking. Over filling it with oil. On new motors it would have to be poorly installed from the factory, or a bad batch of parts. On older motors it's generally down to wear and tear.

In any case if it happens, the advice is "stick something in the air intake" since combustion needs air. But sod trying to find the bonnet latch and then start trying to block the air intake. The best (and quickest) thing to do is intentionally stall it.

IAmATeaf · 15 Apr 2014 at 12:10

WOW, learn something new every day.