S80 T6 engine noise
 

How to tell the difference between the noise caused by sticky filter and noise caused by timing belt?
It is a 2003 Volvo s80 T6 with 120,000 KM.

And how much to replace the timing belt?

Thanks.

Lifter noise is like a tapping noise.
T-belt noise would be like a squeeling noise.

Prices vary for areas.

Hi Tech,
Thanks for your prompt reply!
The noise in engine area is quite subtle with rhythm which sounds like a little bit swing.
So is this some possibility that the noise is caused by lifter rather than timing belt?
Or some problem relative to valval noise/piston slap?
Acturally it is a used 03 volvo s80 T6 (off lease, one owner, no accident, 120,000KM) I plan to buy from a small dealer. This subtle noise is the only thing I am worry about. And I need your kind suggestion on whether I could take it or leave it?
I am a huge fun of volvo

Thank you very much

Also the injectors are pretty noisey on these cars as well. Try to feel around when it is at idle and see if you can feel it anywhere.

Thanks Tech,
The noise does not change its volume, frequency and rhythm whenever the engine is at idle or at high speed. And the noise could only be noticed when I opened the hood, and focused my attention to listen.

It might be a normal engine noise.

You should be able to narrow it down to the Fuel rail pretty easy......I thought my valves were tappin away until I listened to the fuel rail.....loud ass injectors

Thanks a lot for both tech and fs's suggestion.
I will check it again