Okay I made sure I had a look at this yesterday.
Quoting: art b
you should remove the ancillary/serp belt,
I went for this first and it totally confirmed that it is one of the pulleys driven by the drive / aux belt, because as soon as I took the belt off and ran the engine, it was the quietest it has ever been.
I put the belt back on and it seemed a 'bit' better, but I am not sure if that was because by that point it had warmed up and the noise is always quieter when it's warm. So, I went back out first thing this morning to start it again and the noise is still there.
Whilst doing some exploring around the engine, I did notice that the water pump is seeping a little bit, so I'll have to replace that, hopefully at the same time as replacing whatever is making this noise as I will have most of the front-end apart.
I have to say, it sounds like it is coming more from the fan pulley or the centre of the selection of pulley-wheels. Although, it's just too hard to tell exactly with all the noises of the engine. I did try putting a screw-driver against the non-rotating parts of pulleys I could get to, but it didn't really help.
Another issue is I cannot put the belt back on to run certain components at a time to narrow the issue down because the belt runs literally everything, it's a beast of a belt. It's either all on, or all off.
The fan is a thermal viscous fan and I am wondering if anyone knows if they usually have the noise issues mine has?
I think I will end up having to do this, take everything apart, except the fan pulley, then run the engine again, if there is no noise, then it must be the 'bimetallic' spring in the viscous fan.
I did find this in the manual, although the fan-blades seem fine, I couldn't spot anything loose.
I drove to Norfolk and back Friday / Saturday morning and it's fine (touch wood), but it's just annoyingly noisy first thing in the morning. Also, if it is the fan, rather than it breaking and the engine over-heating, I think I have to try and fix it.