There is a difference between an engine that does not start (run) and one that does
not crank over. An engine that does not crank over has to do with the
starter motor and
is a separate issue from an engine that does not run. If
your engine does not crank over refer to the lower part of this guide (starter
What goes wrong?
An engine demands three things to run,
spark. If one of these
components is missing the engine will not start and run.
Let's Fix It
Observing lights and sounds when the engine is not starting is essential,
these steps can give you a direction to proceed which are listed in order of
- When turning the key to the "crank" position does the security light flash? Each
manufacturer disables the engine in different ways when in security
mode. Occasionally the system will become confused due to a glitch or a
procedural error meaning the
alarm system must be
- Run the codes!
a scanner can point you in the right direction or to the system that is not working, simply
plug into the diagnostic port
to gather the code(s) and look up the code
meaning on Google.
- An advanced
CAN scan can be used to evaluate the entire electrical system of the
vehicle which is quickly becoming more useful than the traditional engine
scan, this can help pinpoint the source of the trouble. A CAN scanner starts
at $34.00 on
- It needs to be quiet for this next test, turn the ignition key "on"
without cranking the engine over. You should hear an electric pump in the
fuel tank run for about five seconds (a low hum). If you hear nothing something
has failed in the pump electrical system such as the
relay, fuse or
fuel pump (most
popular). Sometimes you can get the car going with a hammer or large object
by rapping the bottom of the fuel tank which can coax the pump into working
again (this works very well). If the car starts the
fuel pump is bad and needs to be
- Most cars have a
mass air flow
sensor (MAF) which sends feedback data to the computer to trigger fuel to
be allowed into the engine, when this sensor fails the computer will
restrict fuel causing the engine not to start. Disconnect the MAF sensor and try
again, if the engine starts the
MAF needs to
- Next, crank the engine over and listen to how it sounds, does it sound
faster than usual? This can mean the timing belt or chain has failed causing
the engine to have no compression. Perform a compression test to confirm the failure,
observing the engine camshaft
rotation through the oil filler cap on the valve cover will also confirm the
issue (camshaft not turning).
- Check the fuses, this is easy to do and can be done in just a few minutes
using a test light
or visual inspection. Fuses will be either under the hood in the fuse panel
or inside the car in the interior fuse panel which are clearly marked, simply remove the panel lid and begin
- Spraying starting fluid into the
throttle body or a vacuum
line while cranking will help
determine if the problem is fuel or ignition related. If the engine starts
(gas pedal depressed slightly) it tells you the problem is fuel related. If
the engine runs on starter fluid there is a fuel
delivery issue. The car's fuel pump resides at the top of the list for this
system failure. Located in the gas tank the fuel pump is an electrical motor
connected to a fluid pump which fails. Some cars have an access
hatch in the trunk or under the rear seat to help service the pump while
others the gas tank
will need to be removed.
- If the engine does not run on starting fluid the
ignition system could
be to blame. Remove the ignition coil or spark plug wire and set it next to
a good ground (about a 1/4 inch - 8mm) or insert a
light into the boot to
check for spark. If
no spark is observed the most popular reason is a failed
sensor. This sensor is located near the crankshaft at the rear (bell
housing), middle (block) or front of the engine and is pretty easy to change
in most cases (When the crank sensor goes out it usually will not set a
- When the ignition switch is turned on you should hear the main system
relay pull its contacts together which supplies power to the computer
systems. This relay is named different things from each manufacture such as PGM-FI
or Engine Control Relay which is located under the hood in the fuse and
relay panel or PDC (power distribution center). Remove the lid to locate the relay. While
touching the relay have a helper turn the key on, you should be able to feel
the relay work (small click). If not,
test the relay or swap it out for a different relay in the panel to see
if that works, this will work for the fuel pump relay as well.
- Pull a spark plug!
This is easily done and by observing the condition of the plug it can give a clue to the problem. If the spark plugs are dry suspect fuel issues,
if wet with fuel suspect an ignition problem and if the plug is flat black
the electrode is shorted not allowing the spark to jump the gap,
Additional non-starting issues
Watch the Video!
My engine is not
A starter motor
is used to rotate the engine over to begin the combustion process which is
controlled by the ignition key, start button or fob. A flex plate or flywheel
has a gear lined with teeth around the outer ring called a ring gear and is bolted to the
crankshaft which the starter uses to operate. The starter motor pulls the most
amperage of any other component of the car so the
battery must be in
When the engine will not crank over the problem can be isolated to
three separate areas of the car. It could be a
battery or connection issue,
a starter motor
or its trigger system or the engine or one of it's accessories is locked up.
Some problems will be easy to fix while others can be a little tougher.
How much will it cost?
The cost of a starter problem can vary from no charge to hundreds of
dollars, so it is important to get a clear idea of what's wrong. For example a
loose battery cable costs nothing to tighten, just a wrench. Repair shop or
dealership labor times for a starter replacement can generally range between
$85.00 to $280.00 depending on location (some manufacturers locate the starter
under the intake manifold), the part can cost between $80.00 to $220.00.
Let's get started
Repairs are in order of difficulty.
- If the lights go dim or out this can mean one of two things (this can
be accompanied by a ratcheting sound) either the
battery is weak and the
battery needs to
replaced which typically happens between 3 and 4 years or the
battery cables are
loose. There can also be
corrosion on the
battery terminals inhibiting the current flow which must be cleaned.
- When the key is turned to crank the engine do you hear
nothing and do the dash lights stay bright? If so look to see if the security
light is flashing which tells you the
security system must be disabled.
If the light is not flashing try to put the car in neutral and crank the
car, if it starts the gear range sensor (neutral safety switch) is bad. On
standard transmission vehicles check to see if the floor mat is lodged under
the clutch pedal not allowing it to be fully depressed.
- The next step is to check the
starter system fuses and
starter relay which will be
located in the fuse panel (PDC - power distribution center)
under the hood. The location of these
components will be listed under the lid of the panel, in your owner's manual or
you can ask our mechanics for locations.
Replace any blown fuses.
- If the security light is not flashing have a helper hold the ignition
key in the crank position or rapidly press the start button while tapping the starter housing with a hammer,
if the engine starts the
starter needs replacement.
The starter solenoid
(small round electrical component ttached to the starter motor housing) is responsible
for the starter motor operation and must receive a voltage signal from the
ignition switch. If everything before this point looks okay you need to
test the solenoid trigger wire for power when the key is in the crank position to determine the condition of the starter.
The starter motor is usually underneath the engine and on the right or left side at the rear of the
engine block (it can be under the intake manifold like on some Nissan, Cadillac and
Infiniti V8 engines. In this case it's best to find the wire in the loom or at the
relay). Please use our starter
motor and trigger test guide to help with this issue.
Ask our technicians (free)
Article published 2021-08-08