'95 940 turbo noises when driving and starting

Hi All,

I own 1995 Volvo 940 base sedan with an optional turbo engine B230FT.
I got the car when it had 115k miles and now it's at 120k miles. It's
a good car overall and I enjoy driving it.

There are some small things such as certain noises which sometime make
me a little nuts.

First, when I start a car in the morning it would make this noise
similar to old steam train engines but at a higher pitch. It's like
chu-chu-chu-chu. And it's coming from the engine compartment. When at
idle I can hear it just fine, as a matter of fact it's louder than the
engine.
Could anyone tell me where it might come from? Is it engine knocking?
Squeaky belts? Something else?

Second, the creaks and squeaks from the plastic parts. I would
appreciate any advice on how to quite them down.

Third, when I am braking from around 30-40 mph I hear a creak coming
somewhere from the front of the car. Same sound when I corner at 10-20
mph. Any idea where it might come from. When I was buying the car my
mechanic told me that the front strut was leaking and I should think
about replacing it. Could this be related to the suspension . Anyone
had similar problems?

I really would appreciate any comments on this subject.