likely valves. just have your valves adjusted at the dealership, not a big job really but it should be done by someone who knows what they're doing.
Why is your 1993 Altima Nissan making a clicking noise but does not start?
You need to check your starter or your starter selenoid.
The 2001 Nissan Altima GXE might make a clicking noise and then turn off because of a bad solenoid or bad starter. This sound could also be due to a weak battery.
a clunk noise over bumps
It sounds like a connecting rod bearing going out. The only fix it to have the motor rebuilt before it goes out. If you wait until the engine blows you will have to buy another engine because of the damage that will be done.
timing chain making a noise?
A clicking noise in the engine of a 91 Ranger could indicate a problem with the valves. A valve lifter in the engine may be worn or stuck.
It is common to have a knocking or clunking noise of a 99 Nissan Altima, even after the struts have been replaced. This may be due to worn ball joints. It is best to replace the ball joints, too.
bad throw out bearing
I have the same car with the same clicking noise right after you start the engine. The noise stops shortly after starting. There was a recall from Chrysler for this problem. Contact your local dealer regarding this matter.
Possibly the lifters?!?
The Battery is shot and you need to replace it.