Any idea what this noise is?

[c.morewood]

http://i120.photobucket.com/albums/o187 ... 22_004.mp4
As you turn the key the hp pump pressurises the fuel. At the same time this noise sounds drowning out the pump pressurising. It sounds like someone forcing the air out of the stretched neck of a balloon.
You cant hear it inside the car, which is why I've just noticed it. Should I be worried?

[CitroJim]

Chris, I've heard this noise on another HDi and over a long period too.. The owner was not concerned and it didn't seem to cause any issues...

It appeared to emanate from the fuel filter and I believe it may eventually have gone away when the filter element was replaced...

I'd say nothing to be overly concerned about - more an annoyance than anything else...

[c.morewood]

Great! Thanks Jim. I should've mentioned that there is a smell of diesel at the end of the journey, but can't find a leak anywhere. I'll try a new filter.

[Peter.N.]

Can't actually hear anything from your video but nevertheless I would concur with Jim. The noise that I suspect you have was quite common on early Hdi's and does emanate from the filter, why I don't know, and why its stopped I don't know either unless its due to the filter element as Jim suggests, but nothing to worry about.

Peter

[CitroJim]

Chris, one thing... If you can smell diesel then check the 'U' shaped pipe that runs from the end of the HP pump to the fuel rail.. The one on the HDi I referred to cracked and leaked on a union but the crack was so tiny and insubstantial that the leak was barely a leak if you know what I mean... More of a smell...

It was only when the leak got just a little worse and some dampness could be observed that it became clear where the leak was...

The memory is a bit dim now but that may have had some bearing on the disappearance of the noise... It was your reference to the smell of diesel that got a little more of the old memory in action!

[RichardW]

There's a bi-metallic strip in the bottom of the filter, which controls whether or not the fuel is routed via the heater block. This can vibrate and make a right old racket - my Xantia was really bad till I replaced the filter (complete unit) as it was leaking.

[c.morewood]

I just had a look, took the filter housing off its bracket and there was some wetness underneath and on the front of the engine, didn't see that before, I've wiped it off and will have a look when I'm back from Shetland.
The noise seems a little quieter. Thanks everyone.