The pic shows the right hand end of the engine. The silver on the left is the plastic covers over the engine.
The plastic bit is the swirl valve actuator mechanism.
There's a vacuum actuator which pulls the swirl valve arm to open the valves at the right time.
If the arm's come off then the swirl valves aren't being opened and high rev performance will be affected.
Cheers, Kev
02 plate C5 2.2 Hdi Exclusive SE (now 170k miles 03/21).
Used to have:- Xantia 1.9 TurboD SX. 1996 Blue & 1998 Silver Activa. + 1992 BX TZD Turbo.