Citroen Synergie 2.0 HDi engine tapping noise

[Swell]

New here! Hoping that someone might have an idea what the issue is with my Synergie 2.0 HDi.

There's a tapping sound which appears from about 1100 rpm upwards. It's a tapping sound, not really a knocking like big end or something. I've had it checked at a Citroen/Peugeot garage and they thought it was probably tappets rather than the other potential culprits which are the injectors and the crankshaft pulley/other associated pulleys & bearings. There's no smoke at all which suggests injectors are ok, and the sound seems to be coming from the top of the engine rather than the auxiliary / timing belt area. However, they really weren't sure and said they'd have to charge for a proper diagnosis.

Here's a YouTube clip which demonstrates the tapping. I tried recording under the bonnet but there's so much other noise that its hard to pick out the tapping, so I did it with the bonnet down. It's louder near the wheelarch, but that's just because there's a clear route to the engine with no sound damping in the way.

http://www.youtube.com/watch?v=-QJsbdG2oMA

If anyone has any ideas that would be very much appreciated!

[oneday]

hi tried to look at video it just says its private and wont show it

[Swell]

Sorry about that - I've now set the clip to Public so you should be able to view it.

[Swell]

Hi,

Any thoughts on this one? I'd really welcome ideas.

[Swell]

Just realised I had https not http in the youtube clip address - now amended!