Intermittent car start is a common issue that the owners face quite often. It means your automobile worked well until you turn off the engine and restart it; it sometimes just stands still. This symptom makes you confused about the possible reasons.
Yes, there are some main causes that lead to this trouble. It can come from different vehicle parts, such as the battery, sensor, fuel, etc.
Knowing how each component works and affects each other allows you to understand the root of the problem and find the proper solutions.
This article will provide you with some tips to solve the issue of my car starts sometimes and sometimes it doesn’t.
Why My Car Starts Sometimes And Sometimes It Doesn’t?
Electrical Problems
Crankshaft Positioning Sensor
The crankshaft positioning sensor is the first reason you might think of when a car starts sometimes other times it won’t. If the sensor is not functioning properly, you can not start your vehicle.
It causes your vehicle to start again after a lot of cranking.
You can diagnose this problem by using an OBD2 scanner tool. However, even if it is somehow still working and eventually your automobile starts to move, there is no guarantee that the battery is not damaged.
Battery
Battery Voltage
One of the other possible reasons for a car sometimes starts sometimes doesn’t is insufficient battery voltage.
You should make sure that there is enough power to turn on your vehicle. Use a voltmeter to analyze and determine how much voltage your battery owns.
The ideal voltage to start your motor is between 12.4 and 12.6 volts. If it’s less than 12.4 volts, you should recharge your battery and turn on the engine again to see if it works.
Wires And Cables
Anything wrong with the wires and cables can prevent the electricity flow and hinder your vehicle from starting. It can be corroded battery terminals, broken or loose connections, or faulty wires.
You may face one of these symptoms more if you don’t do mechanical inspections regularly.
Dirt or debris can also affect the battery terminal’s function. You can get rid of this problem by cleaning the battery with a solution of warm water and baking soda.
While removing contaminants, dirt, and debris, ensure the mixture does not touch other parts under the filler caps.
Starter Motor
Motor
A faulty starter motor can cause a “car sometimes starts and sometimes doesn’t” situation. If you hear a loud grinding sound, the mounting bolts are loose and can not move the flywheel.
Tight them to make sure all the components in the motor work as expected.
However, there are some moments you may think: “Hey, the mounting bolts are tight, but why my car starts sometimes and sometimes it doesn’t?” Then, it can be because the flywheel doesn’t crank the motor at the correct level.
You can check it by spinning the pinion gear and see whether anything is wrong with the movement of the apparatus.
Starter Solenoid
The engine compartment may produce a repeated clicking sound related to a faulty solenoid. Besides, there may be audible noise under the capote, which means there is something stuck inside that leads to an unengaged magnet coil.
If you hear any of these strange sounds when starting your vehicle, it can be a sign of a damaged starter solenoid that disables the starting system.
Ensure that the starter solenoid is connected fully and the wires are uncontaminated so that the starting system is able to work correctly.
Engine
Engine Ignition Coils
Bad or exhausted engine ignition coils can also lead to the issue of my car starts sometimes and sometimes it doesn’t.
This coil plays an important role in power transmission for an internal combustion engine. The electricity can’t come to the spark plugs to start the vehicle without it.
Engine Flywheel
The flywheel is located between the transmission and the engine. It cranks the engine by rotating the pinion gear. Take out the starter motor, put the transmission to neutral mode, and spin the crankshaft to analyze the mechanism.
The root problem probably lies in the pulley, which brings some troubles with the alternator or serpentine belt. Moreover, the flywheel’s missing or broken teeth can be why sometimes car starts sometimes it doesn’t.
Problems Related To Fuel Filter
Dirty Fuel Filter
If your automobile struggles to start, it can be because of the clogged fuel filter. This faulty fuel filter can block the fuel flow into the lines to turn on the vehicle.
Thus, it requires more pressure in the pump to push the fuel through the clogged filter. Working over its limit can damage the pump, explaining why my car starts sometimes and sometimes it doesn’t.
Injectors
The fuel injector is responsible for transmitting the fuel to the engine. When the dispersion is bad (not at the correct pressure level), it can develop problems with improper starting.
If there is direct damage to the injectors, you are more likely to have trouble delivering fuel and starting your vehicle.
Engine Problems
Apart from electrical and fuel delivery problems, the issue of my car starts sometimes and sometimes it doesn’t also comes from the engine.
Low engine compression can cause power loss and make the generator difficult to start. It means the engine is dying gradually due to the cut down on power.
To diagnose the compression, you need a compression tester. The average compression to allow the cylinder to operate properly is 90 to 100. If the result is under 90, you should open and check the engine.
Hopefully, it’s only because of the valve issues; otherwise, the problem is deeper, and you need more analysis and repair.
How To Fix?
Fixing Method
There are some ways to troubleshoot the problem of sometimes my car starts and sometimes it doesn’t.
When you know the reason is the bad battery, make sure you charge it enough, check and clean the connections inside if possible. With an unhealthy battery, think of replacing it with a new one.
A dirty air filter blocks the air going through, and in turn, the car struggles to start. Change it as soon as you see it’s black and oily.
As for the problem comes from the starter, diagnose for any corroded or damaged parts or burnt wires. Replace the starter if needed.
Similarly, in case you have an issue with the ignition switch or fuel pump, bring your car to the repair shop for professional fixation. In short, you should change those components that require regular replacement.
For the engine matter that causes the situation: my car starts sometimes and sometimes it doesn’t, do a compression test. If it fails to perform, then its life span will end soon. Changing the engine will solve the issue.
Scan your vehicle for cores with an OBD2 scanner tool to determine whether the coil or fuel injection renders the car to start intermittently. The easiest way is to bring your vehicle to a mechanic to sort out the problem.
How Much Does The Fixing Cost?
If your car has a bad battery or spark plugs, it will cost around $200 for replacement. When the problem lies in electrical parts such as the coil or starter, you can expect to pay a maximum of $500.
The valve-related job will cost around $1000. You can learn how to clean idle air control valves to protect your automobile and save some money.
Other fixations of the engine such as rebuild or replacement requires $2000 and $5000 respectively.
FAQs
What Are The Signs Of A Bad Starter?
To identify a bad starter, listen to any strange sound it makes. It can be grinding, whirring, and high-pitched.
However, you can hear these noises if you have a battery or alternator issue. Make sure you fully charge your battery before analyzing the starter.
How To Tell If Your Fuel Pump Is Going To Be Bad?
Bad fuel pump usually has one or more of these symptoms
- It’s difficult to start the automobile
- You hear a whining sound from the fuel tank
- The engine sputtered and stopped
- The pump stalls and gets hot
- Car surging
- Engine loses power
- The car doesn’t start
How To Know If It’s A Problem With Starter Or Alternator?
You can follow these steps to diagnose the problem.
- Switch on the key to see whether you can start the engine. If not, it can be due to a drained battery or a bad starter. Listen for a clicking sound.
- Open the cap and slightly shake the battery’s connections.
- Use a hammer to hit the starter lightly, then start the vehicle again.
Conclusion
We’ve just looked at the problem: my car starts sometimes and sometimes it doesn’t with the three main possible causes and its details.
Any battery, fuel system, or engine issue can prevent your car from starting properly. Depending on the situation, you can find different solutions to solve.
You can rebuild or change the damaged components. To avoid high costs, make sure you keep your battery power at a high level, keep other parts clean, and stay away from corrosion.
If you don’t have enough knowledge about automobiles, bring your vehicle to the repair shop. We’ve informed you of the fixing price for your reference.