How do you stop a runaway engine?

[Vic Evans]

Reading a recent post reminded me of one of my GD's car, a Fiat 500 from memory, which suffered an engine runaway.
She had no idea what to do so took the sensible option & ran away herself whilst the engine destroyed itself.
Other than blocking the engine air inlet or putting the car nose first against a wall before dropping the clutch in the hope it would stall the engine I'd also have no idea what to do.
Is there an accepted way of dealing with this problem?

[Steve Walsh]

Block The air intake, but not with your hand, If available a CO2 Extinguisher in the intake, shut off fuel or air supply. or as you say, try and stall it...... I had a truck years ago that the turbo failed and started dumping engine oil into the intake and started to runaway, I put it in a high gear and put the brakes on, scary few moments with plenty of noise and smoke.
Also had a Yamaha FS1E do it, I turned the fuel tap off and retreated to a safe distance till it stopped!

[NewcastleFalcon]

There is a bit of a thread here which recounts some tales of such things.

viewtopic.php?p=632255#p632255

and here's another from Doo

Anyway, I report this because I experienced my 1st diesel runaway
I had stripped the engine well enough to install a new timing belt & water pump kit & full service inc new coolant.
It mattered not a jot that I filled the new filter and cracked the injectors, it would NOT bleed . I even had a leisure battery hooked up to give more cranking power...

I decided I would have to resort to the same stuff I used to start wife's DV6 after it's major rebuild. So, brake cleaner was sprayed into the (I believe) MAP Sensor) port and she fired a good few times, but still wouldn't run long enough to build up pressure....

until it did

It started, crack craack craaack, rrrRRRrrrr____rrRRRRRRRRRRRAAAAAAAAAAAAAAAAAAAAAHHHHHHHHHHHHHH

It took about 3 seconds to decide what to do. There were no huge plumes of thick grey smoke, so she was clearly now running on whatever oil the brake fluid has watered down in the intercooler (stupidly, I forgot I had cleaned my wifes cooler to gleaming, so it was fine) and it was running on basic home made diesel.

So I put both hands around the trunking from the air filter to the turbo and squeezed. A second went by before it slowed by a few hundred RPM, then slower and slower and slower, but it was still grunting at about 800RPM or so and my hands were getting painful as this was going on 2 minutes..... Thankfully she stopped!

It took me a few minutes of deep breaths to get my heart rate back to an acceptable 200BPM Then I mulled over what had just happened.

Suffice to say, I believe this may have happened sooner or later because the engine is a mess. Coated in more oil than the Amaco Cadiz. The previous owner clearly didn't think to change the crank case breather filter and the oil has blown out of every orifice.

So later, I'll be pricing gaskets and engine cleaner as well as removing the intercooler to stick my power washer nozzle right up it

I won't lie, I almost came close to requiring new underwear..... That noise

On the upside, I saved the engine twice! As I was changing the timing belt, I pulled off the pulley to find a bit of metal jammed between parts of the inside of the pulley and having chewed through the plastic belt casing, it was now starting to chew into the belt!!!!

Mad day all round!

Neil

[bobins]

As Steve says - either a CO2 fire extinguisher or something like a sturdy item of clothing* stuffed into the air intake if you can get to it.

*- lots of other items can be used to blank off the air intake, but it's likely someone might be able to lay their hands on a bit of clothing.

......not suitable for stopping a lorry, bus, tank, or other industrial engine as they'll just eat it and spit out the confetti

[mickthemaverick]

Just another option, same method but I used the car's handbook from the glove compartment across the air intake, the plasticised cover makes a pretty good seal!

[Michel]

Just another option, same method but I used the car's handbook from the glove compartment across the air intake, the plasticised cover makes a pretty good seal!

I've also done this!!