Yes belt plus idler pulley as you say. If it isn't valves it could potentially be carbon cannister, worth unplugging to make sure its not that causing the noise (it will throw an error code when unplugged)
I would tighten up the engine mount bolts to spec as well just to be sure
Do you have a video/audio of the noise? My 1.2 is a little tappy but nothing I have ever worried about
There have been lots of posts on the forum about tappy 1.2s and that's because they just are, even when they are in spec
Yeah I think it’s worth a try, but mine is petrol so I’m unsure if the petrol ones have that canister. But I’ll deffo search it up and have a look because I’ll try anything at this point lol.(and I’ll go round torquing bolts near the noise).
And I will deffo get a video of it soon and try and post it in this thread,(new to the forms unsure on how it all work yet lol)
Like you’ll understand when I post a video, it’s nothing major at all it’s just very annoying and it’s making me feel bad for using it while it taps.
Plus I think the 02 sensors are faulty as I believe the car is running not rough but… lumpy on idle, like it really wants to cut out but it manages to stay alive, so I don’t know if that will make a tapping noise due to I don’t know, un burnt fuel, less stopping power for the pistons and it tops out at the top of the engine causing a tap.
But yeah I’ll get a video soon lmaooooo.