190E Knocking, Timing...

[adras]

The engine on my '89 190E 2.6L started knocking very loudly - like a disel.
The car was burning oil badly for about 6 months, I just read on here that the oil consumtion is due to bad valve seals - will be replacing these in few days.

Q1. Is the knocking due to a loose timing chain? The lifters look fine. I took off the valve cover and everything looks fine - except for smoke coming out the valves(again I think due to the vavle seals).

Q2. When replacing the timing chain - do I need to adjust the timing? Or will a new chain will be already made so that the timing will be set (which I doubt).

Q3. The oil consumption, how crucial is it to also replace the valve guides and not just the seals? Do I need special tools for this - I know that I need a specific tool to remove those sprints on the valves there (that will be tough to find). Do I need some kind of specs to for the valve guides when inserting the new ones?

Q4. Also the car has hard start (not the OVP) I think maybe the IVC - not sure where that is though - photo would be a great help here. The car is also running very rich (white smoke out of the exhaust when idiling on warm engine). Where do I have to connect the volt meter to correctly adjust the mixture?

Thank you in advance for your expert opinions.

Cheers.

PS: I will keep this thread updated with the progress.