Car no-start troubleshooting

Engine no-start diagnostic • How to check the battery • Why the car won't start

Note, the information contained in this guide is for educational purposes only and cannot substitute for the advice of professional mechanic or authorized dealer. Don't attempt to service your car if you don't have proper knowledge and tools, you can be injured and your vehicle could be damaged. Take your car to a dealer or a repair shop.

Foreword

I receive so many questions on vehicle no-start problem diagnostic. In this page I have tried to write down some most useful simple tips that may help you to find out why your car won't start. These tips may also prevent you from being overcharged by dishonest mechanics - you will always be charged more at a garage if you look unfamiliar with the car mechanical aspects.

If you want find more technical information about your car - diagnostic procedures, repair information, service bulletins, recalls, wiring diagrams, how to reset "Maintenance required" light, maintenance schedule, etc. follow this link:

Where to find technical information about your car

Only a few basic things are necessary for the engine operation

1. Fuel (To be exact proper air/fuel ratio, normally it is about 14/1)
2. Spark (in appropriate moment)
3. Proper timing (the valves should open and close only in appropriate time)
4. Compression in the cylinders (Normal compression is 120 - 170 psi. The engine won't start if the compression is lower than 70 - 80 psi.)

Plus, to start the engine, the battery, the starter and the starter circuit should be OK.

If the engine won't start - there's no magic - one of these things is probably missing. Most often it's a spark- or fuel- related problem, but often it could be very simple things like dead battery.
If the car won't start, check simple things first:
Make sure you have a fuel in the tank, oil in the engine and the battery is OK, follow this link - How to check the battery

Now simply answer the questions, press "Yes" or "No" (If it's blue, follow the link).

- Do you hear the cranking sound when you're trying to start your car? (Yes No )
- When you switch the ignition ON before starting a car, does the "check engine" light come ON? (Yes No )
- When you switch the ignition ON, do you hear fuel pump buzzing sound from the gas tank area? (Yes No )
Before your engine died, did you experience any prior events such as:
- leaving the lights ON overnight (Yes No)
- driving through a deep puddle, or washing the engine compartment? (Yes No)
- trying a jump start? (Yes No)
- having only a little fuel in a tank? (Yes No)
- having had the engine repaired recently? (Yes No)
- the engine was overheated? (Yes No)
- extremely low oil pressure? (Yes No)
- unusual noises such as knocking, pinging, whistling? (Yes No)
- smoking from exhaust pipe? (Yes No)
- strong smell of a gas? (Yes No)

Now, let's try again. Turn off the radio, try to crank the engine one more time, and listen carefully. Is the cranking sounds different than it used to be? If it's different, does it looks like the engine being cranked by the starter too slowly? (Yes No)
Is the engine being cranked too fast? (Yes No)

If you don't hear the cranking sound when you're trying to start your car, means that starter doesn't work - something could be wrong with the starter, starter wires, relay, or the battery is dead. Also check battery terminals, they could be corroded or loose.
How to check the battery