Most of the time it's because you have your car in the wrong gear. The key will not start the ignition if your car is in anything but park or neutral.
Another common cause with vehicles equipped with any sort of ignition engaged steering wheel lock is that the steering wheel is turned and putting pressure on the locking mechanism. Try turning your steering wheel (left or right) in such a way that the pressure is taken off of the ignition lock while turning the ignition key.
A caveat to anyone owning a Nissan with a non-electronic key (mostly 1990s):
This is a shoulder-stop type key, which means that all the force of each insertion into the lock is absorbed by the shoulders.
The keyway is deeper than the blade of the key, and, after a while, shoulder wear allows the flats on the key to travel past the wafers inside the lock that the key should operate.
This causes a "false lockout" condition, which can be overcome by simply pulling out slightly on the key as you turn it. If you have ever tried to have a misbehaving key copied, you probably already know that it works no better or not at all. This is because the key shoulder is the reference point for the key machine guide, and it is missing.
Bottom line: take your Nissan to a qualified locksmith, have them decode the key and cut a set of original keys for you. Unless the locks are badly damaged from overuse of bad keys, an original key should work very smoothly.
Groucho
I am not sure what causes this, but I have had times when my ignition key would not turn. The solution to the main problem is to turn the steering wheel slightly. This usually allows the ignition key to turn.
You need to put a key in the ignition and turn it.
turn key over turn key over
move the steering wheel while attempting to turn ignition key
I usually take the key out, turn it, and put it back in ignition to start
Wrong key?
Your ignition also locks your steering and at times you need to move the steering wheel a little and at the same turn your ignition key. Then you should be able to turn the key and start the engine. Hal
Worn or badly cut key, wheels turned cramping the steering wheel so that there is pressure on the key cylinder. Cylinder itself bad.
How can I take out the key from the ignition key in a BMW 325i 2001. I can turn on the engine but the key doesn't come out when I turn off.
it is either the key is worn out or the key cylinder in the ignition is worn out.
is it a ford? push the key in further and then turn it
It's the wrong key maybe!