Could it be the head gasket has gone or suspect itto go
how did we get from squeak under the bonnet to head gasket....first thing you should do in take the auxiliary belt off and then start the car and see if the noise is gone, if it has then check all the pulleys for play, binding etc to narrow down which part is causing the noise, it maybe simply a stretched auxiliary belt.
I don't know about the petrol engine but on a diesel the water pump is driven by the cam belt and therefore can't slip and make a squeal.
the noise when clutch is released sounds like the clutch/ thrust bearing.
All I was trying to get at is; no point trying to scare the bloke with stories of blown head gaskets Etc. when the original question was about noise on engine start up. Fair enough, Pete mentioned later on about loss of coolant but that can be caused by lots of different things some cheap some not so cheap.Read Posts 1, 2 & 3... nothing is guaranteed especially a diagnosis from a written note...
Anyway... read & see how we got there... its using / losing coolant... last time I looked an Aux belt or clutch cant do that! Touche?
OK if the water / coolant pump is driven by the cambelt, I didnt know.
Otherwise good points.
Posts 6 & 7 are important here, Pete asked if it could be the HG...
I told him the HG can fail if a coolant system issue is ignored, that is true. He also said that he knew there was a radiator problem when he bought it which had a temporary fix done, everyone is entitled to know :-
a) what they SHOULD do
b) what the worst consequences of NOT doing what they should do are
c) where to look for the root cause.
No-one Posting in here can be 100% confident that they have covered off accurately all possibilities.
We just give a steer or the benefit of experience.
You added to the latter, it's up to the OP to work his way through the suggestions Posted.
No worries Frogger, we're all trying to help