Alright here are my situations right now my engines has 193,000 miles and has just recently decided to give me some problems.

So far I've done a valve adjustment and switched out the extremely loose timing belt hoping that it would get rid of the horrendous engine noise (valves).

Here are the problems:
The horrible engine noise, it sounds a lot like the valves but there adjusted correctly and the engine just makes a clanking noise when its running, it gets quieter when the engine is reving higher but sitting at a stop light and idle just drives me nuts have that noise coming from my car.
The other problem Im having is that when I start my car the oil light is fine but once I start driving and the car warms up when ever I come to a stop light or have to idle the tach drops immediatly down to 100-300 rpms wanting to stall out and the oil gauge moves from blinking at 1000 to solid red as it goes down. This makes is so that I have to hold the car at 1000 rpm or else it will stall. Theres the proper amount of oil in the engine but could this have some thing to with the oil pump and screen or possible something else.

Thanks for the help.