Strange Engine Sound?

The problam with the top hose could be caused by a duff thermostat. So as you have done that it should be ok now.

Radiator cap. 

 I see you said your car has aircon? have you tried it with the air con turned off ? or the belt removed.? My race car made a similar noise when I initially bought it as a road car. This was easily cured by throwing the compressor in a skip!!Big Smile 

 The noise from the clutch is most probably the thrust bearing which is unlikely to cause you any problems.

 OOps sorry missed the post where you cured it. DOH!Confused

No worries :slight_smile: