I have an 2007 Versa. I had the same engine noise sounding like the solid cam lifter. I tried everything from synthetic oil to different oil filters with no luck. The engine is especially noisy when it is cold. After a year of putting up with this I finally tried 89 octaine gas and also put in a can of injector cleaner and after half way into the tank the car was running much better. During the second tank of 89 octaine the lifter noise went away. So much for Versa's running on regular gas.
he he he
The fuel in the cylinders exploding
You need to be more specific. There are many kinds of engine noise! From your description it can be anything from a blown rod to a belt!
use ngk spark plugs
loose exhaust
when the engine weres down
The fuel in the cylinders exploding
u joint
it is time to change bearing on that pulley
Loose belts
Wheel bearing?
lifters