Could be lots of things, one that isn't thougt of is a fuel injector sticking. Can of injector cleaner can't hurt anything.
that's just the sound of the steel bits cooling down
My left wheel ticking while driving was causes by brake pads that did not fit. As explained poor fit.
A 97 Maxima can have these symptoms because of a bad alternator. If the alternator has low output there can be a ticking and eventually the engine will stop running.
I have the same ticking noise and it seems to be louder on hotter days. I was told by the service tech it's due to the synthetic oil being thinner. I have my doubts, but that's what they said. Still researching for the answer myself.
you need to adjust the valves
lifters
The ticking sound is coming from the valve lifters. When the oil filter is changed, air is introduced into the system, which causes air bubbles to form in the oil. This causes the valve lifters to "leak down", which is what causes the ticking sound. It can take several days for the bubbles to dissipate. It's annoying, but harmless.
The electronic ignitor keeps ticking when it is off because it is cooling off. The air hits the probe when the probe is hot, and it is trying to condense, or cool off, which causes the ticking.
Some of the causes of shin pain due to running is caused by the constant impact associated with running. Sharp stabbing pain is one of the main symptoms that you will experience if you have this condition.
there is a dust cover behind the front rotors they sumtimes bend slightly and it causes the ticking and crackling
The fuel injectors make the ticking noise you hear at startup, especially when the engine is cold (colder temperatures).
It's a rocker arm tapping at valve stem. Hydraulic lifters (hydraulic rocker mounts) are the common reason for the ticking. If it doesn't go away when the engine heats up, consider replacing the lifter where the ticking comes from.