To troubleshoot a Nissan Altima engine that will not start, users should first eliminate simple issues, such as a dead battery. If a clicking sound is heard when the key is turned, users should ensure the battery cables are tightly connected to the terminals.
If the cables are tightly connected, car owners can check for corrosion on the terminals. A buildup of corrosion can cause a weak connection and prevent the car from getting enough power to start. If the cables are corroded, they can be cleaned with a wire brush. If corrosion is not the issue or they have been cleaned, the next step is jump starting the battery to see if this fixes the issue. Users can use another vehicle or a trickle charger to charge the battery. If this does not enable the car to start, there are several others things to check.
If the engine tries to turn over, but does so slowly or makes a grinding noise, the starter could be at fault. This can be diagnosed by removing the starter and having it tested at a local auto part stores.
Another common cause of a car not starting is a low fuel level. To check this, users should turn the key and wait a few seconds to see where the needle stabilized on the fuel tank gauge. If the fuel tank is empty, this can be remedied by filling the vehicle up with gas using an approved gas can.