Car Engine Turns But Won’t Start

Possible Causes

If your car engine turns but won’t start, there are a few possible causes:

No spark – This could be caused by a faulty spark plug, ignition coil, or distributor.
No fuel – This could be caused by a faulty fuel pump, fuel filter, or clogged fuel line.
No air – This could be caused by a clogged air filter or a faulty mass airflow sensor.
Compression problems – This could be caused by a blown head gasket or worn piston rings.

Troubleshooting Steps

To troubleshoot the problem, you can follow these steps:

Check for spark – Remove a spark plug and hold it against the engine block. Have someone crank the engine. If you see a spark, then the ignition system is working properly.
Check for fuel – Press the Schrader valve on the fuel rail. If fuel squirts out, then the fuel system is working properly.
Check for air – Remove the air filter and inspect it for any blockages. Also, check the mass airflow sensor for any damage.
Check for compression – You will need a compression tester to check the compression in each cylinder. If the compression is low, then the engine may have a mechanical problem.

Repair Options

Once you have identified the problem, you can then repair it. Here are some of the most common repairs:

Replace spark plugs – Spark plugs should be replaced every 30,000 to 60,000 miles.
Replace ignition coil – The ignition coil can fail over time, especially if the engine is subjected to high temperatures.
Replace distributor – The distributor can also fail over time, especially if it is not properly lubricated.
Replace fuel pump – The fuel pump can fail if it is clogged or if the electrical connection is faulty.
Replace fuel filter – The fuel filter should be replaced every 15,000 to 30,000 miles.
Replace air filter – The air filter should be replaced every 12,000 to 15,000 miles.
Replace mass airflow sensor – The mass airflow sensor can fail if it is contaminated with dirt or debris.
Repair head gasket – A blown head gasket can be repaired by replacing the gasket and resurfacing the cylinder head.
Replace piston rings – Worn piston rings can be replaced by rebuilding the engine.

Conclusion

If your car engine turns but won’t start, there are a few possible causes. By following the troubleshooting steps outlined in this article, you can identify the problem and repair it. However, if you are not comfortable working on your own car, it is best to consult with a qualified mechanic.