Are you straining that car self-starter?

I met Joe at a local garage on Entebbe Road during the late morning hours. He told me he had spent the entire morning at the garage, having called his regular mechanic Ssali after his BMW suddenly stopped in Entebbe on his way from Kampala. The car had refused to start, Joe narrates. He says while driving on the Expressway, he could not resist pressing the accelerator in a mini race between him and another driver.

As the other driver got close, Joe stepped up, hitting the 140kph mark. Suddenly, the car went bizarre, sparks came from the engine area, as well as several other sounds, that forced Joe to stop by the road side for a quick check.

He could smell burning rubber from the inside, though when he opened the bonnet, nothing looked out of place. At this point he decides to resume his journey. Unfortunately, the car refuses to start, several attempts at trying the ignition do not result into much.

Joe is that driver that will not allow their car to be checked by any mechanic or washed from any washing bay. But this was also besides the fact that he was on the Entebbe Expressway, where getting mechanical help is not that easy.

This is when he calls Ssali, a person he describes as reliable and always on hand. On arrival, Ssali recommends taking the car to the garage where it would be easier to assess the actual fault.

Faulty starter

Several checks at the garage reveal that the car starter was faulty. A starter also called a self-starter, cranking motor, or starter motor is a device used to rotate an internal-combustion engine so as to initiate the engine’s operation under its own power. Starters can be electric, pneumatic, or hydraulic.

According to www.autoelectro.co.uk, when you turn the key in your car’s ignition, the engine turns over and then cranks. In order for the engine to crank, there must be a flow of air into the engine, which can only be achieved by creating suction (the engine does this when it turns over).

If your engine is not turning over, there is no air. No air means that fuel cannot combust. The starter motor is responsible for turning the engine over during ignition and allowing everything else to happen.

On the engine, a flywheel, with a ring gear attached around the edge, is fitted to the end of the crankshaft. On the starter, the pinion is designed to fit into the grooves of the ring gear. When you turn the ignition switch, the electromagnet inside the body engages and pushes out a rod to which the pinion is attached.

The pinion meets the flywheel and the starter motor turns. This spins the engine over, sucking in air (as well as fuel). As the engine turns over, the starter motor disengages, and the electromagnet stops. The rod retracts into the starter motor once more, taking the pinion out of contact with the flywheel and preventing potential damage.

Hard start

Ssali explains that often, car owners pay little attention to the starter of the car. He says many cars develop a habit that mechanics refer to as hard start, especially in the morning. Sometimes, this hard start is associated with the car battery losing power. However, Ssali says, the hard start is also linked to the starter since in most cases,  the hard start is experienced in the mornings when the car has been static for long hours.

He further states that when drivers try to start the car and it takes longer than usual to crank, we keep pushing the ignition which at times results in the engine finally cranking. On other occasions, when mechanics realise that the starter has problems, they hit it with a metallic object, which also sometimes forces it to eventually work.

However, according to Ssali, drivers should pay more attention to servicing the car starter.

Components

The starter has seven components, each serving a unique purpose. The armature, an electromagnet, mounted on the drive shaft and bearings for support. It is a laminated soft iron core which is wrapped with numerous conductors loops or windings.

The second component is the commutator, a section of the shaft at the rear of the housing on which the brushes run to conduct electricity. The commutator is made up of two plates attached to the axle of the armature. These plates provide the two connections for the coil of the electromagnet.

Solenoid

The third component are the brushes which run on a section of the commutator at the rear of the housing, making contact with the contacts of the commutator and conducting electricity.

The solenoid, another component, contains two coils of wire that are wrapped around a moveable core. The solenoid acts as a switch to close the electrical connection and connects the starter motor to the vehicle’s battery.

The plunger works by using the connected vehicle battery and the solenoid to push the plunger forward, which engages the pinion.

There is also a lever fork, connected to the plunger so when the plunger is pushed forwards, so is the lever fork. This process then activates the pinion, another component that is a unique combination of a gear and springs.

Once the starter is engaged, the gear is extended into the gearbox housing and is engaged with the flywheel. This spins the engine to begin the combustion process. The housing holds the starter fields in the housing with screws. This can consist of two to four field coils connected in series.

Energised by the battery, this converts the coils into an electromagnet which then turns the armature. When the armature coils are powered, a magnetic field is created around the armature.

Care

Ivan Ssebuliba, a mechanic and professional driver, notes that if a driver was observant, they would notice when a component of the starter is getting worn out. At this point, some of the components, especially the brushes can be replaced, giving the starter a new lease of life.

In Joe’s case, however, all indications were ignored as he admits. On many occasions the car gave him problems especially in the morning but he persisted until it started and off he went. Ssali explains that the brushes in the BMW’s starter wore out, but the insistence later affected other components until the fateful day when the covering plate was affected, causing the sparks and killing the starter beyond repair. Joe had to part with Shs400,000 to buy a new starter.