Hdi 110 'run on'.

[trapa57]

Hello,

My Hdi 110 estate has started to 'run on' for say half a second when I turn off the ignition, causing the exhaust to bump under the car. Or, (perhaps) the exhaust is coming loose and bumping on the under side of the car when the ignition is turned off. This happens when the engine is warm.
I have looked from the back end, the rear box is very rusty but has all 3 rubber mounts in place, the remainder of the exhaust under the car is looking pretty good. I haven't looked closely at the front end of the exhaust yet.
Any suggestions or ideas would be most welcome .

Thanks,

Paul

[CitroJim]

Paul, I'd say this is caused by a drippy injector that's not quite shutting right off and dribbling a little. This'll make the engine bump around on its mountings quite alarmingly for that split-second and be the cayse of the exhaust bumps. If that's the only time you hear it.

It's also likely to break the rubber bush in the top engine mount torque reaction arm that goes to the inner wing.

So, best to get it checked and rectified. Firstly, have the injector flow rates checked on a Lexia and then do a leakoff test by running the injector leakoffs into four plastic bottles and observing the leakiest. That should be the suspect one.

[myglaren]

Leakoff test kit:



Click for full size image.

[citroenxm]

Run on is NOT caused by injector dribble. Its caused by the Pressure Regulator on the END of the pump below the out put pipe!

Had this on a W reg HDi, swapped the regulator unit and all was well..

Its swappable in situ, theres two T30 torx screws hold it on. It then pulls outwards with a bit of a pull as theres a small seal on the end of the shaft.

[RichardW]

I'm with you Paul -but if the run is on <1s then this is probably normal. I suspect that the bush in the inner wing mount has gone west - the first symptom of this is a rattle on shut down, that sounds just like the exhaust banging - mine's been doing it for a while, and the bush has totally separated now, so it also sounds bad on start up. Must get a new one on order.....

[trapa57]

Hi,

Thanks guys for your replies. I will start at the 'cheap seats' by replacing the engine mounts then move on if necessary.

Paul

[RichardW]

Here's the broken mount from my car (it's supposed to be one piece!): http://www.frenchcarforum.co.uk/forum/v ... 7&p=374781" onclick="window.open(this.href);return false;

New mount only available complete, but it's just under £30 from Citroen (part no 1839 46). I thought about trying to get a poly bush, but all the websites only list sets for various cars, so it's difficult to find anything suitable - and at only £30 not really worth the bother. When other things stop breaking and absorbing money, I'll get one ordered up and replace it!

Not too hard to remove - unbolt the two electovalves and lay them on top of the engine, then undo the through bolt at the front yoke, then the 3 16mm bolts holding it onto the wing - the bottom one is a bit awkward to get on! Then separate the two halves - you will need a 16mm open ender or flat ring to do this bolt up again once on the car, as you can't set the angle before you refit it - I just used an adjustable as I only have a 16mm cranked ring that won't fit in there - must get an alternative to that as well.

[taffy]

ive run on and hunting and i think its injectors now reading pugs forums on hdi