Starter Spinning but Not Engaging: Identifying the Issue

Starter spinning but not engaging is a problem that many vehicle owners have been facing for years. Each vehicle’s starting motor is essential because it supplies the initial force needed to crank the engine.

Yet occasionally, you can find yourself in a position where the starter turns on the engine but does not start it, leaving you stuck. We’ll outline a step-by-step guide for fixing this issue in this post so you can get your car back on the road.

How To Fix Your Starter Spinning but Not Engaging?

To fix your starter spinning but not engaging, you have to check the battery voltage, check the starter Bendix, check the starter solenoid contacts, check the cabling, check the starter connections, check the power delivery with jump test, and finally check the starter motor.

• Check the Battery Voltage

Low battery voltage is one of the primary causes of a starting motor that spins but does not connect to the engine. Low battery voltage implies that there is not enough power in the car battery to start the engine, which results in the starter motor spins without turning the engine on.

We will cover how to check the battery voltage in this stage as well as what to do if it is low. A multimeter is required to check the battery voltage. Voltage, current, and resistance may all be measured with a multimeter.
Connect the red lead of your car multimeter to the battery’s positive terminal and the black lead to the negative terminal after setting the multimeter to the DC voltage setting. The battery voltage will then be shown on the multimeter.

A battery should be at least 12.6 volts in voltage when it is fully charged. Lower than 12.6 volts indicates a poor battery that needs charging or replacement. Several things, like keeping the lights or radio on, severe weather, or a broken alternator, might cause a weak battery.

Connect a battery charger to your car battery and follow the manufacturer’s directions to charge the battery. The battery may need several hours to completely charge. It is needed to replace the battery if it cannot be charged or if it can be charged but still has low voltage.

• Check the Starter Bendix

The starter Bendix is a gear system that interacts with the flywheel of the engine to crank it. The starting motor will spin without connecting to the engine if the starter Bendix malfunctions. Here, we’ll go through how to inspect the starting Bendix and what to do if it’s broken.

Remove the starting motor from the engine before inspecting the starter Bendix. Look for any evidence of wear or damage on the starting drive gear’s teeth that interact with the flywheel. Next, look for any evidence of wearing or damage on the Bendix gear, which moves alongside the starting drive gear.

The Bendix must be changed if either gear’s teeth are worn, damaged, or missing. Bench testing is another method of starting a Bendix inspection. For this test, the starting motor must be taken out of the engine and connected to a bench test device or a battery. Put the starting motor under power and watch the Bendix gear move.

Bendix gear has to be changed if it stops moving altogether or moves slowly. Wear and tear, a lack of lubrication, or a defective starting solenoid are a few causes of a bent starter Bendix. To prevent additional harm to the starting motor and the engine, it is crucial to quickly replace a broken Bendix.

• Check the Starter Solenoid Contacts

The starting solenoid is an electromechanical switch that connects the beginning motor to the battery with an electrical signal. It is made up of a wire coil that, when powered by the battery, produces a magnetic field. A plunger that connects the battery to the starting motor is pulled by the magnetic field.

The starting motor will spin but won’t connect with the engine if the starter solenoid or its stick solenoid contacts are broken. In this phase, we’ll go over how to inspect the starting solenoid, as well as how to deal with defective stick solenoids.

Find the starting solenoid on the starter spinning motor and then check its stick solenoid connections. For any indications of corrosion or damage, examine the connections connecting the starting motor, battery, and solenoid.

Next, look for any evidence of wear or damage on the stick solenoid contacts, which are housed inside the solenoid. It is needed to clean or replace the contacts if they are corroded, damaged, or unclean. Bench testing is a different method of starting solenoid inspection.

For this test, the starting motor must be taken out of the engine and connected to a bench test device or a battery. Put the starting motor under power and watch the solenoid plunger move. The solenoid has to be changed if the plunger gets stuck or goes slowly.

• Check the Cabling

The starting motor may spin but fail to engage with the engine due to corroded or loose wiring. We will go through how to examine the cabling in this phase and what to do if it is rusted or loose. The battery cables should first be visually inspected for any indications of deterioration, such as breaks, cracks, or corrosion.

The starting motor may not get enough power to engage with the engine if the cable connections are slack due to corrosion, which can also produce electrical resistance. The battery cables should be properly cleaned if they have corrosion or dirt on them.

To get rid of all the gathered rust and grime, use a wire brush and cleaning solution. When cleaning the cords, make careful to detach the batteries. Next, examine the connections between the starting motor and battery wires.

Verify that the connections are secure and not slack. Make the connections tighter using a wrench if necessary. If the car battery cables are in good shape, look for any evidence of damage, such as cuts, breaks, or frayed wires, in the wiring harness. The wire harness must either be fixed or replaced if it has been damaged.

• Check the Starter Connections

The starting connections should then be examined if the starter motor and battery cables are both operating properly but the starter motor is still unable to start the engine. The electrical connections at the starter solenoid and the motor itself are included in the starter connections.

Find the faulty starter motor first, then check the connections on the starter. It usually sits close to the transmission or the flywheel of the engine. Once found, look for any obvious corrosion or damage on the electrical connections. Use a wire brush or even sandpaper to clean any corroded or broken connections.

It’s crucial to check if the cables are undamaged and the connections are tight and secure. Next, look for any wear or damage to the starting motor housing. The starting motor may not operate if the casing is broken. The bad starter motor should ideally be replaced if there is any damage.

• Check the Power Delivery With Jump Test

A set of jumper cables and a fully charged battery are required for a jump test. The positive (red) jumper wire should first be connected to the positive terminal on the dead battery, and then the other end should be connected to the positive terminal on your vehicle battery that has been completely charged.

The negative (black) jumper wire should then be connected to the negative terminal of a fully charged battery, and the other end should be connected to an appropriate ground point on the engine or chassis. Try starting the engine while the jumper cables are attached.

If the starting motor turns on and the engine starts, it’s probable that the battery has to be changed. The starter motor may now need to be changed if it still won’t engage. If this is the instance, there may be an issue with the motor.

• Check the Starter Motor

The starting motor itself must be examined as a last resort if all the preceding steps have been performed and the starter motor still does not engage with the engine. A damaged starter motor may prevent the engine from starting or may cause the motor to spin independently of the engine.

It is important to take the starting motor out of the car and test it on a bench. Bench testing entails directly attaching the starting motor to a battery and evaluating its operation. The starting motor should first be removed from the car, as directed by the manufacturer.

When the starting motor has been removed, physically check it for any signs of wearing or damage, such as cracks, corrosion, or worn-out parts. Next, use jumper wires to connect the starting motor to a fully charged battery.

Attach the positive cable to the starting motor’s positive connector and the negative cable to the metal housing of the starter motor. When the cables are attached, turn on the battery and check the starting motor’s operation.

Conclusion

It might be annoying when a starting motor rotates but does not connect to the engine, but you can fix the issue and get your car back on the road by thoroughly following this starter spins but does not engage guide. Summing up the key concepts we’ve covered:

• The step-by-step procedure to identify the issue involves examining the starting Bendix, solenoid contacts, cabling, and starter connections, and performing a jump test.
• Examining the battery terminals and cables, measuring the battery voltage, and confirming the battery’s cranking potential are all steps in determining the battery voltage.
• Listening to clicking sounds, looking at the pinion gear, and examining the ring gear are all steps in evaluating the starting Bendix.
• The starting motor must be taken out of the car and put through a bench test by being connected to a fully charged battery to be checked.

Always remember to take the proper safety precautions when dealing with electrical components, and if you are unclear about any step, ask a qualified mechanic.