Hi guys, I need you input on this

The subject is:
A6 2.7T
Yr: 2000
Millage: 77500

There has been recently two new noise coming from the engine. The first and one that occurred most recently is a clunking noise that is there right after start up and then disappears (within a minute or two). The second is the sound of a chain clattering against something metallic, this will happen within a few minutes of staring from cold but not at startup and can be sopped by pressing on a silver cylinder and the top of the engine, about the level of the valve cover gasket (on the passenger (right) side of the engine) however the noise is not there constantly and is only present for a few seconds and then stops.

The mechanic I took it to said it could be the valve chain tensioner beginning to ware, from my description can anyone concur or suggest another cause for these noises. Also the mechanic seem to think that it was not something that needed changing immediately as the noise only happened on startup from cold when oil pressure is at its lowest and is not constant but intermittent.

Many Thanks
James

 

Your mechanic sounds right to me.