Cl203 couple of issues

[John81]

I have c180 cl203 coupe 2006 1.8 petrol. Couple of things I'm looking for advice on. I've had a slight ticking, whirring/rattling/squeaking noise from engine at lower speeds whilst in higher gear. Most notable at 30ish mph in 4th but it does it at other speeds too. Thought maybe water pump or exhaust. Also the temp takes a while to rise and when it does it rarely goes above 80 and then goes down at higher speeds. And finally does anyone know if its normal to have the engine quieten down when you engage clutch from idle. The idle is louder that when putting clutch down. Not sure if this is normal (theres not a huge diff but its noticable) or if the clutch release/pilot bearing is on way out? Any advice welcome. Cheers