Car Won't Start Then Starts Later

Car Won't Start Then Starts Later: Troubleshooting the Intermittent No-Start

So, your car decided to play a game of hide-and-seek with its starting capabilities. One minute it refuses to even cough, the next it purrs like a kitten. This frustrating intermittent no-start problem is a common automotive gremlin, but with some systematic troubleshooting, you can often pinpoint the culprit. This article will guide you through the most likely causes and how to diagnose them.

Understanding the Problem: Why the Intermittent Start?

The key to understanding why your car won't start sometimes lies in recognizing that the issue isn't always a complete failure of a single component. Instead, think of it as a weakening link in the chain of events that starts your engine. Sometimes, a partially failing component might work intermittently, leading to that frustrating "it starts later" scenario.

Common Culprits Behind an Intermittent No-Start:

Here's a breakdown of the most frequent offenders, listed in a general order of likelihood and ease of checking:

1. Battery Problems: The Usual Suspect

• Weak Battery: A weak battery is the most common cause. Intermittent starting often indicates a battery that's nearing the end of its life or hasn't been properly charged. Check the battery terminals for corrosion and clean them if necessary. A low battery voltage reading (using a multimeter) confirms a weak battery. Consider battery load testing for a more accurate assessment. Also, inspect the battery cables for any damage or loose connections.

• Alternator Issues: Your alternator recharges your battery while the engine runs. A failing alternator might not adequately charge the battery overnight, resulting in a no-start in the morning, followed by a successful start later in the day (once the alternator has had a chance to recharge the battery somewhat during driving). A low voltage reading while the engine is running points towards a failing alternator.

2. Starter Motor Malfunction: The Cranking Conundrum

The starter motor is responsible for cranking the engine over. An intermittent problem with the starter could manifest as a no-start sometimes, with a successful start at other times. This often involves a clicking sound when you try to start the car. This could be due to a failing solenoid, worn-out brushes, or other internal starter motor problems.

3. Ignition System Hiccups: Spark Plugs, Wires, and Coils

• Spark Plugs: Worn or fouled spark plugs can prevent reliable ignition, leading to intermittent starting. Inspect the plugs for wear, fouling, or damage. Replacing them is relatively inexpensive.

• Ignition Wires/Coil: Damaged or loose ignition wires or a failing ignition coil can disrupt the spark delivery to the spark plugs, causing intermittent starting. Check for cracks, corrosion, or loose connections.

4. Fuel Delivery Difficulties: Pump, Filter, and Injectors

• Fuel Pump: A weak or failing fuel pump may struggle to deliver sufficient fuel pressure, resulting in an intermittent no-start. Listen for the fuel pump's priming sound when you turn the ignition key. A lack of sound might indicate a problem with the pump.

• Fuel Filter: A clogged fuel filter restricts fuel flow, similarly causing intermittent starting difficulties. Replacing the fuel filter is relatively simple and inexpensive.

• Fuel Injectors: Problems with the fuel injectors can intermittently disrupt fuel delivery. Diagnosing fuel injector problems typically requires specialized tools.

5. Sensor Issues: The Silent Saboteurs

Various sensors monitor engine conditions. A faulty sensor (e.g., crankshaft position sensor, camshaft position sensor, mass airflow sensor) can disrupt the engine control unit (ECU)'s ability to control ignition and fuel delivery, resulting in intermittent no-starts. Diagnosis of sensor issues usually requires specialized diagnostic tools.

6. Other Potential Causes

While less common, other issues could contribute, including:

• Immobiliser problems: Check your car key and key fob batteries.
• Security system malfunctions.
• Loose or corroded wiring connections: Inspect all connections, especially those related to the battery, starter, and ignition system.

Seeking Professional Help:

If you've gone through this checklist and your car still exhibits an intermittent no-start, it's time to seek professional help from a qualified mechanic. They possess the diagnostic tools and expertise needed to identify more complex problems.

Remember safety first! If you are uncomfortable working on your car, don’t hesitate to seek professional assistance. A properly diagnosed and repaired issue will save you time, money and frustration in the long run.