lumpy on switch off

[conny]

over the last couple of days when i switch the ignition off the engine seems to rock or vibrate, for want of another word.as if its trying to run on and rocking? its never done this before and i cant think why it would.i did think engine mounting but as im not really technically gifted thats a guess.any suggestions folks ?? by the way its an 05 19cdti zdth [150]

[Dan_BlackSRi]

What engine? EGR issues can cause this.

[KevinG]

didnt they used to call this pinking, used to be down to timing issues i think before the days of EGR and such stuff, showing my age

[conny]

yeh thats what i thought.on a petrol engine i'd say the timing was out but i have'nt got a clue about diesel engines ?

[Dan_BlackSRi]

It will be a slightly sticking EGR mate.

[conny]

cheers dan,i'll take it out and give it a good scrub.had it 16months now and haven't taken it out.dont know if its ever been taken out .its done 55k now so must be due a scrub.and i'll do that boost sensor as well.will i need new gaskets? and whats all this blanking off business ?

[the-wizard]

If that don't solve it , with it being a diesel it can only be 1 thing!!, the diesel supply isn't being cut off immediately upon switch off.

[Chocki]

On the 1.9s there is an electric throtle which shuts the air off to the engine when you turn it off, if this is sticking or the EGR is sticking open, air can get past into the inlet manifold and cause exactly what you describe.

[the-wizard]

[quote=the-wizard;1239635]If that don't solve it , try removing the 'throttle body' that has a butterfly flap in it and it may not be openening + closing fully', ''forgot this earlier''. give it a good clean + work it by hand (its spring loaded and firm to move by hand).