Are you wondering why your car won’t start? Issues with the starter system are more common than you think, but drivers often confuse them with other car troubles. Read up on bad starter symptoms and learn how to tell them apart from other problems.
What is Starter?
A starter (also self-starter, cranking motor, or starter motor) is a device used to rotate (crank) an internal-combustion engine so as to initiate the engine’s operation under its own power. Starters can be electric, pneumatic, or hydraulic. In the case of very large engines, the starter can even be another internal-combustion engine.
Internal combustion engines are feedback systems, which, once started, rely on the inertia from each cycle to initiate the next cycle. In a four-stroke engine, the third stroke releases energy from the fuel, powering the fourth (exhaust) stroke and also the first two (intake, compression) strokes of the next cycle, as well as powering the engine’s external load.
To start the first cycle at the beginning of any particular session, the first two strokes must be powered in some other way than from the engine itself. The starter motor is used for this purpose and it is not required once the engine starts running and its feedback loop becomes self-sustaining.
How the starting system works
To make an engine start it must be turned at some speed, so that it sucks fuel and air into the cylinders, and compresses it.
The powerful electric starter motor does the turning. Its shaft carries a small pinion ( gear wheel) which engages with a large gear ring around the rim of the engine flywheel.
In a front-engine layout, the starter is mounted low down near the back of the engine.
The starter needs a heavy electric current, which it draws through thick wires from the battery. No ordinary hand-operated switch could switch it on: it needs a large switch to handle the high current.
The switch has to be turned on and off very quickly to avoid dangerous, damaging sparking. So a solenoid is used – an arrangement where a small switch turns on an electromagnet to complete the circuit.
The starter circuit;
The starter switch is usually worked by the ignition key. Turn the key beyond the ‘ignition on’ position to feed current to the solenoid.
The ignition switch has a return spring so that as soon as you release the key it springs back and turns the starter switch off.
When the switch feeds current to the solenoid, the electromagnet attracts an iron rod.
The movement of the rod closes two heavy contacts, completing the circuit from the battery to the starter.
The rod also has a return spring -when the ignition switch stops feeding current to the solenoid, the contacts open and the starter motor stops.
The return springs are needed because the starter motor must not turn more than it has to in order to start the engine. The reason is partly that the starter uses a lot of electricity, which quickly runs down the battery.
Also, if the engine starts and the starter motor stays engaged, the engine will spin the starter so fast that it may be badly damaged.
The starter motor itself has a device, called a Bendix gear, which engages its pinion with the gear ring on the flywheel only while the starter is turning the engine. It disengages as soon as the engine picks up speed, and there are two ways by which it does so – the inertia system and the pre-engaged system.
The inertia starter relies on the inertia of the pinion – that is, its reluctance to begin to turn.
The pinion is not fixed rigidly to the motor shaft – it is threaded onto it, like a freely turning nut on a very coarse-thread bolt.
Imagine that you suddenly spin the bolt: the inertia of the nut keeps it from turning at once, so it shifts along the thread of the bolt.
When an inertia starter spins, the pinion moves along the thread of the motor shaft and engages with the flywheel gear ring.
It then reaches a stop at the end of the thread, begins to turn with the shaft and so turns the engine.
Once the engine starts, it spins the pinion faster than its own starter-motor shaft. The spinning action screws the pinion back down its thread and out of engagement.
The pinion returns so violently that there has to be a strong spring on the shaft to cushion its impact.
The violent engagement and disengagement of an inertia starter can cause heavy wear on the gear teeth. To overcome that problem the pre-engaged starter was introduced, which has a solenoid mounted on the motor.
There’s more to a car starter system: As well as switching on the motor, the solenoid also slides the pinion along the shaft to engage it.
The shaft has straight splines rather than a Bendix thread, so that the pinion always turns with it.
The pinion is brought into contact with the toothed ring on the flywheel by a sliding fork. The fork is moved by a solenoid, which has two sets of contacts that close one after the other.
The first contact supplies a low current to the motor so that it turns slowly – just far enough to let the pinion teeth engage. Then the second contacts close, feeding the motor a high current to turn the engine.
What are common bad starter symptoms?
1. Something sounds off.
One of the symptoms of a bad starter is a clicking noise when you turn the key or push the start button. However, a starter can die without making any sound at all, or it may announce its impending death with whirring and grinding noise so listen up!
2. You’ve got lights but no action.
If you try to start the engine only to find that the dashboard lights up, but the engine doesn’t power up, you might have a problem with the starter.
3. Your engine won’t crank.
Is your engine not revving up, even after attempting a jumpstart? At this point, it’s time to call roadside assistance and get your car to the nearest Firestone Complete Auto Care. If a jump start won’t fire up your engine, nothing other than a certified technician will!
4. Smoke is coming from your car.
The starter is part of your car’s electrical system and subject to blown fuses and short circuits. When you’ve been desperately attempting to start your car, the starter can overheat making electrical issues and the accompanying smoke more likely. If you see or smell smoke, call for help rather than turning the key harder, again!
5. Oil has soaked the starter.
Your starter can usually be found on the driver’s side of the motor, just below the left bank of cylinders. If you pop the hood only to find that your starter is drenched in engine oil, your bad starter might be a sign of another problem an oil leak.
Unfortunately, what starts out as a few drops of oil can slowly and sometimes unnoticeably turn into an expensive problem, so keep an eye out for oil leaks to avoid starter issues of this nature.
What causes starter problems?
A variety of problems can lead to a bad starter, including:
- Loose wiring to and from the starter
- Dirty connections
- Battery corrosion
- Damaged or worn-out parts in the starter system
- Oil leaks
How do you troubleshoot starter problems?
Assuming you’ve already tried to start and jumpstart your car, try one of the following troubleshooting tips.
1. Look under the hood.
Check the battery and battery cables to see whether everything’s in working order. A weak or dead battery, or even faulty battery cables, could be causing the problems with your car, not the starter.
2. Tap the starter.
Try lightly tapping the starter a few times with a hard object, making sure not to pound it. In some cases, this gentle tapping can help power it back up, since you’ll be tapping the electrical components back in contact with each other.
Know how you can sometimes bang on the side of an old TV to bring the picture back into focus? It’s kind of like that. But like your wonky television, your car may only react to this fix temporarily just long enough to get you to your nearest service center.
3. Adjust the transmission.
Let’s say your car’s automatic transmission is in the “park” setting but the car won’t start. If that’s the case, try starting the car in “neutral.” If it starts in “neutral,” there may be a technical glitch that’s preventing the car from starting in “park,” like a faulty neutral safety switch.
4. Check the fuel gauge.
We know it seems silly but…is your gas tank empty? That’s a sure reason why your car isn’t starting!
The quick fix for a bad starter is jumpstarting your car so you can get it on the road, at least temporarily, and get the problem checked out by a qualified technician. If a jumpstart doesn’t do the trick, you’ll most likely need to get the car towed and have the starter repaired or replaced. We can help with that.