What should I be investigating

[Corey Hill]

Hey guys, had my 2.5 1997 for about 5 months now and I’m in love with it, done 5000 miles so far already!
What I will say is this car has been nothing but a pain in the ass so far in regards to maintenance I replaced the blower motor because it sounded like an attack helicopter, had an alarm issue which I got rectified, there’s a few I’m stumped by

Front left knock, sounds like someone is playing a drum down there, when I’m by myself it’s knock squeak knock squeak, I asked the old man for his advice, he’s a mechanical engineer and has a lot of knowledge when it comes to almost any vehicle, we had the wheel off, investigated, everything looks solid, no play anywhere, I’m confused! Took him for a drive to listen and for the first time ever no noise at all!! It’s always noticeable by myself
What could be causing such a loud knock constantly?

Not sure if this is normal, obviously there’s a certain level of deceleration noise if you were to downshift or whatever and let the revs drop but in 1st and 2nd gear I seem to have a really noticeable whine when accelerating or decelerating, that seems to be most noticeable in the 2000 revs range. 3rd gear is very very slight and as you change up there’s no noise at all, I don’t have any gearbox or clutch issues in regards to shifting.

Any ideas on what to investigate for these? I’m off work at the moment so I’d like to take this time to get ontop of things, cheers!