Car keeps going

[gazzawazza]

My daughter has a Peueot 306 (M reg I think) and she's just told me about a problem. The other day, after driving about 35 miles she said that when she turned off the ignition the car continued to run, even when she removed the key. She said it was revving up, roaring like it was going to take off and it went on for about ten minutes. Can anyone tell me what could be causing this?
Thanks in advance.

[jake-the-peg]

Is it a petrol or a diesel?

[gazzawazza]

It's petrol.

[tonyav]

It could be pre ignition,but i would not have thought it would ocur on a car as modern as yours. well not if it has fuel injection anyway.

[jake-the-peg]

I asked because diesels have a shut off valve that can stick open.

I would guess that it's a combination of a sticky accelerator cable and a worn key switch.

[tamborine]

over-heated engine....check fluids

[jake-the-peg]

Overheating and preignition can cause run-on - I get it on my old MG but if you have a petrol engine "roaring like it was going to take off" that implys the engine is still running with power to the spark plugs. so the ignition is still running despite the key being removed. - hence dodgy lock suggestion.

The roaring implies that the gas is still being supplied at some rate. So possibly a sticky cable of a spring used to return the pedal or carburetta may have failed or come loose

[gazzawazza]

Thanks very much everyone, I'll look into those suggestions.

[hughjass]

could it have been the radiator fan running rather than the engine???