this site might help ------>
The 2006 Nissan starter can be found on the right hand side of the engine. The starter will be near the bottom of the engine.
Maybe its the starter?!?!?!
starter is located next to engine at front of transmissin
No - See Link
Remove starter and bring to auto parts store for testing
You have to be underneath the car and have very nimble hands.
The starter is located beneath the throttle body. Remove the intake tube, then the starter bolts can be removed and the starter replaced.
could be a worn starter ring gear, most likely.
under the hood
Take the steering column housing off (usually held by 4 screws from the bottom) and remove the starter cap from the back of the ignition cylinder. In a Nissan, the ignition cylinder usually has a T shaped pin which turns the starter. if you can start your vehicle by turning the starter cap with a screw driver, you probably don't have an issue with the starter.
There are many different reasons why the Nissan Altima won't start. It could have a dead battery, a bad starter or even the engine. It is best to take it to a mechanic for them to diagnose the problem.
check the starter