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Where To Hit A Starter With A Hammer (Solved)

You don’t generally want to beat on parts of your car. However, sometimes, when a car doesn’t start, a smart rap in the right place can get things moving again. You’ve probably heard of this trick before.

image of a starter and solenoid

I’ve learned it firsthand and have used it frequently.

Last December, we had an ice storm come through town. Overnight temperatures dropped to single digits. After the ice storm, a snowstorm followed and added a foot of snow.

Now, I hate the snow. It’s part of why I went to college in Pensacola and why I go back down there every chance I get. But life didn’t cooperate, so I was stuck in the Midwest for this disgusting storm.

There I was, curled up next to my fireplace in flannel pyjamas and a cup of hot toddy I was about to enjoy. At that moment, my friend texted. He was driving through town, had stopped for a bite to eat, and his car wasn’t starting. Could I come to jump his battery?

If it had been anyone else, I would have told him to call a tow service. I dislike snow that badly. But for my good friends, I’ll leave my hot toddy and flannel pyjama pants to go into the storm.

We jumped his car, but it still wasn’t starting. “Got a bad starter solenoid,” I mutter. “Got a tire-iron handy?” He rummaged in the back of his trunk for a minute before coming around with short tire iron.

Perfect.

I reached into the hood (thankfully, this was a Honda Civic, so the starter was easily accessible) and hit the solenoid three times.

“Try it now.”

He got in the driver’s seat and tried to crank the engine. His car started instantly.

“Don’t turn it off until you get home,” I warned as I climbed into my own car and got out of the cold.

Symptoms Of A Bad Starter Solenoid

If you are trying to start your car and only hear a single, weak “click” (or no sound at all), then it is highly likely that your start solenoid has gone bad.

When you turn the key into the “start” position, there should be measurable power to both sides of the solenoid.

The starter solenoid is an electromagnet relay that engages the pawls of the starter with the flywheel.

With age or cold weather, the pinion in the solenoid tends to get stuck. The starter gear can stick mechanically, or corrosion in the wires inhibits the electromagnet from engaging.

Either way, a few gentle taps will help dislodge the solenoid gears and get them to spin freely again. (Be careful not to hit too hard) You can also jar the solenoid a little bit to help the wires make enough of an electrical connection for a moment.

Around the shop, we sometimes joke about how dropping an object will fix it. (I call it a 12-inch calibration.) Tapping the starter is a way to get the starter going temporarily.

I find that rapping on a starter is only going to work a handful of times. Generally, this is a stop-gap measure to get you home, and then you need to have the starter replaced immediately.

However, in the case of my buddy, it was just the cold weather that seized his starter motor. As the weather warmed, his starter continued to work, and the next winter was more mild, so he never had problems. (I should probably follow up

Some other problems that could be causing trouble.

Solenoid Wire

Often, the starter is on the bottom of the car, and the connection terminal is exposed to the elements and accumulates extra corrosion. (I especially see this on cars that drive on a lot of salted roads.)

Sometimes, hitting that terminal with a toothbrush and some Coca-Cola will eat the corrosion off the connection and get it working again. Or, if it is really corroded, soak it in some baking soda and vinegar and then rub it with a wire brush.


Dead Battery

If you are getting a rapid clicking from your starter (tick, tick, tick, tick, tick) it could indicate a dead battery. See if your radio works. If all of the electronics are dead, your battery voltage is too low, and you need to jumpstart the car. If you have a voltmeter, check the battery for juice and make sure that it is showing over 13.1 volts.


Corroded or Loose Battery Cable

Loose battery cables are so easy to overlook. Start by grasping them and trying to wiggle them. If they wiggle, they are loose and are not delivering the connection you need.

Additionally, if there is heavy corrosion around the battery terminal, try using the Coca-Cola orbanking soda and vinegar trick I talked about earlier to remove the corrosion. A little agitation with the wire brush should get them shining again.

Burnt Out Wiring

In my experience, this is very rare. However, I’ve seen it happen enough that it is the first thing I test when there is a bad battery.

Basically, you want to bypass the entire wiring harness and see if you can jump the starter directly.

To do this, turn the key into the “on” or accessory position and use jumper cables to run a line from the positive side of the battery to the terminal on the starter motor.

If the wiring is burnt out or if there is a relay that is malfunctioning, the starter will start the car when positive voltage is directly applied.

If nothing happens, this is confirmation that the starter motor is dead and needs to be replaced.


Dead Fuel Pump

If your car turns over but does not start, it is a dead fuel pump. Have someone turn the key on while putting your ear by the fuel tank. You should hear a slight whine, indicating the fuel pump is primed and ready to start.


Loose Ground Wire

This goes along with the loose cables at the battery terminals. Follow the wire from the battery to where it is connected to the car frame or engine block. If it has been cut or is detached, this will cause starting problems. One time my dad was having difficulty getting his semi truck to start, and we found that the ground cable was loose. Easiest fix I ever had to do.

How A Starter Works

It helps to have a basic understanding of how a starter works.

A starter is a motor that turns the engine once the key turns the ignition switch. Once the engine begins firing on its own, the starter gear disengages.

To engage the starter gear, the starting solenoid runs the starter gear up a pinionwhere the gear teeth mesh with the engine’s flywheel (or flex-plate). After a few quick spins of the engine crankshaft, the engine’s combustion takes over, and you release the key, allowing the starter motor to disengage.

Once the engine starts, and you turn the key back into the “Accessory” position, the electric circuit for the starter solenoid dies, and the starter gear comes back down the pinion.

It’s a fairly simple electromagnetic relay, but since the solenoid is built into the starter motor, both need to be replaced at the same time if one part of it fails. (On some older cars, there is an external solenoid that can be replaced, but these are rare today.)

A starter will wear out with age. Like most motors, a starter motor uses armature brushes made from graphite that wear over time. Rust can also accumulate on metal connections inside of the motor housing.

Inside the solenoid, it does not take much rust to interfere with its performance.

How To Fix A Starter With A Hammer

chevy 350 starter

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. If that doesn’t work. I move to heavier taps on the starter motor housing.

If that still doesn’t work, you can have someone try holding the key in the start position while you tap it.

After you start your car this way, it should be driven to a shop for a complete repair. You are dealing with worn-out brushes or a failing solenoid, and the starter needs a mechanic to replace it.

However, this is a handy trick to have in your back pocket in emergencies or when trying to avoid a tow fee. Any auto shop will be able to install a new starter for you.

Plus it’s always fun to do this around a bunch of drunk people. It truly is the best party trick.

Symptoms Of A Bad Starter

  1. A car that cranks slowly.
  2. A car that clicks but doesn’t start.
  3. The interior lights dim when you try to start, indicating excessive draw.
  4. There is a grinding noise when you attempt to start the car.
  5. There is a whining noise when attempting to start.
  6. There is a gear scream noise after starting as the starter fails to disengage.

Frequently Asked Questions

How long will tapping the starter work?

I have had it last for a few months. Generally, I have to tap it once or twice the first month and then tapping more and more frequently until it finally stops working. (I grew up really poor, and vehicle repairs got pushed off until the last minute).

Why do I have to hit my starter with a hammer?

A few good taps help to dislodge what is causing it to stick. On a weak starter motor, the vibration can help give the motor the help it needs to get free and start spinning. In some cases, the brushes are worn and need help contacting the commutator bars.

Zachary Drumm

Hey! My name is Zachary Drumm! This site allows me to test new tools, piddle around in the garage, and share the insights I get from flipping cars and houses. When it comes to tools, home improvement, and being a “shade tree mechanic,” you’ve come to the right spot. If I’m not in the garage creating content, you’ll find me outside, running, canoeing, and traveling. My goal is to empower more people to be self-sufficient.