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Why Starter Motor Fails and Types of Starter Motors in Automobiles

Do you know about the types of starter motors in Automobiles? Or Wonder why the starter motor fails sometimes? So before knowing the answer to these questions let’s just get to know the starter motor first.

The starter motor is an electric motor that starts the engine by turning it over or “cranking” it. It’s made up of a powerful DC (Direct Current) electric motor and a starter solenoid that’s connected to it. A working starter is required for a roadworthy car because an internal combustion engine cannot start independently. Incorrect connections, malfunctioning solenoid switches, or a damaged single-pinion gear can all cause malfunctions. Below mentioned are some of the reasons why the starter motor fails.

1. Although it engages, the engine does not turn

There are a few possibilities if you turn the key and hear the clunk of the starting engaging, but the motor doesn’t turn. A loose or corroded electrical connection is the most common source of this problem. If the starter motor’s internal windings, brushes, or other electrical components are damaged, the beginning motor may not crank the engine. There could also be mechanical concerns, such as faulty bearings inside the starting or teeth in the starter or ring gear that is no longer meshing.

2. Grinding noises

This problem can also develop when the starter gears, which connect the starter to the flywheel, are broken or worn out. However, a grinding sound can be heard from the starter motor itself. In any situation, there is no way to solve the problem. If you detect this symptom, the most significant thing you can do is take action. Because if a grinding starter isn’t replaced, it risks damaging the flywheel, which would be considerably more costly to repair.

3. Smell and noise while turning on

Electricity powers the starter, just like any other mechanical device. As a result, it’s possible that the starter overheats due to excessive and continuous power or that the motor won’t shut off even after the car’s engine has started. When this happens, it’s typical to notice smoke or a foul odour emanating from the engine compartment. This could be caused by a faulty ignition switch or a blown fuse.

4. The starter spins, but the motor does not

The pinion gear on a starter motor does not always engage the ring gear on the flywheel. Instead, the starter uses a Bendix device, which is essentially a large magnetic, to drive the smaller gear out to interact with the flywheel. Because of this, the pinion gear was stretched out to contact the flywheel. If all you hear is a whirring or grinding sound when you turn the key, Now that we have understood some of the reasons why sometimes the starter motor fails, the next thing to know is the types of starter motors in Automobiles.


1. Direct Drive Starter Motor DD

A direct drive starter motor, sometimes known as a DD starter motor, is an electric car starter motor in which the armature is connected directly to the pinion gear. Thanks to this mechanism, the pinion gear delivers the armature force straight to the engine flywheel. The direct drive starter motor has been around for a long time in automobiles. It is a traditional starter motor, which is heavier and larger.

2. Planetary Gear PLGR

These types of starter motors have mostly superseded direct-drive starter motors. It’s a permanent magnet that sends power from the pinion shaft to the armature. The armature spins faster and with increased torque. The purpose of planetary gear is to reduce gear, which reduces the need for high current even further. A sun gear is situated at the armature’s extremity, and three rectangular carrier gears are held stationary inside the ring gear.

3. Permanent Magnet Gear Reduction PMGR

The permanent magnet gear reduction should be lighter, easier to construct and generate less heat. Instead of field coil starters, it has four to six magnet field assemblies. The 12V solenoid has three terminals and is likewise heavy-duty, using less current. The commutator and brushes transfer current directly to the armature because there are no field coils.

4. Permanent Magnet Direct Drive PMDD

Permanent magnet direct-drive (PMDD) turbine generators eliminate rotor winding losses and mechanical energy losses via gearboxes and couplings. The total power converter allows the rotor rotational speed to be more significant for optimal mechanical energy transformation.

5. Off-Set Gear Reduction OSGR

An extended spur gear (Straight-cut Gear) meshes parallel to the pinion gear in the off-set gear reduction starter motor. This extra gear reduces the pinion gear speed by four times that of a direct drive starter motor, resulting in higher torque (Cranking Power).

The armature and pinion gear are not aligned in the reduction gear starting motor. They’re on opposite sides of the axis. The armature drives the reduction gear, and the reduction gear drives the pinion gear.

6. Inertial Starter

Inertial starters turn a pinion and propel it forward towards the ring gear via centrifugal force. The pinion teeth lock into the ring gear and crank the engine while it continues to spin. Inertia starters have the advantage of automatically disengaging after the engine has started.

Let’s Wrap Up

Finally, we’ve gone over the engine starter motor in detail and why it occasionally fails. We also learned about the various types of starter motors, their principles, and how they function. Hope it helps you!

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