To temporarily make a starter work, you should give the starter solenoid (the small cylinder on the starter) or the main body of the starter light, firm taps with a hammer or wood, while someone tries to turn the key, to jar stuck internal parts like brushes or the plunger, allowing electrical contact. This is a temporary fix for a failing starter, usually caused by worn brushes or corrosion, and you need to get it replaced soon.
It definitely works, but be careful when doing it and avoid certain parts of the starter (such as the wiring, any seams, the mounting locations, etc.). Basically, use a bit of common sense, and remember that consistently required percussive maintenance is a sure sign that the motor/solenoid is slowly dying.
How To Start a Car with a Bad Starter (Temporarily)
Tapping the starter with a hammer or a wrench can sometimes make your car start because it can loosen up any dirt, corrosion, or worn parts that are preventing the starter from working properly.
If a little moisture gets in the housing and rusts up the brushes and brush holders, or the brushes are nearly worn out, gently rapping on the starter housing can sometimes free them up, letting them make enough contact to make the starter work.
Grinding noises, like metal chewing on metal, often indicate that the starter's gears aren't engaging properly with the flywheel. A single, loud click usually indicates a faulty starter solenoid responsible for engaging the starter.
Mallet or hammer: These are useful when tapping the starter to start cars, as they can free up stuck components.
Press the Lock button on your remote car starter. Within five seconds of turning it on, turn your key back to the “off” position (or press the start button again). Repeat the on-off cycle three more times—you'll do four in total.
If you have a manual transmission, push-start your car to bypass the starter and get the engine started. If you have an automatic transmission, gently tap on the starter repeatedly with a hammer or piece of scrap wood. This should knock debris or corrosion loose so you can start the car.
A single click when you turn the key or press start may indicate a dead battery or an issue with the starter. If jump-starting your vehicle works, it was likely an issue with the battery. If not, your starter could be malfunctioning.
Yes, you can by using a portable jump starter or a battery charger. What safety precautions should I take when jump-starting my car alone? Wear safety gloves and goggles, and follow proper procedures to avoid sparks and potential battery acid exposure.
To clarify, you aren't going to fix a starter with your hammer, but as I've shared, I've sometimes gotten them going again. I start with some very light taps on the solenoid portion, and then I try to start the car. Just 3 or 4 taps is all it should take.
Start by connecting a jumper box or jumper cables from a good vehicle's battery to yours. After waiting a few moments, try starting your vehicle. If it doesn't start, your starter may be the problem, since no matter how charged the battery is, your car won't start without a working starter.
If the starter engages but does not disengage when you let go of the key, the solenoid is likely bad and the starter may suffer significant damage as a result. Sometimes your car starts, sometimes it doesn't. Intermittent operation can be a sign of a failing starter solenoid.
A weak or dead battery is often mistaken for a starter motor issue. Turn on the headlights: If they're dim, your battery may be low on charge. Use a multimeter: Check the voltage. A fully charged battery should read around 12.6 volts.
OTOH, a starter with a bad armature segment responds well to tapping or banging with a hammer. The vibration from the tapping/hammering usually causes the armature to move to the next segment, allowing the engine to start.
Understanding these causes can help in troubleshooting and preventing further damage.