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My Engine Won't Turn Over

Dan Ferrell writes about DIY car maintenance and repair. He has certifications in Automation and Control Technology and Technical Writing.

An engine no-crank condition can be hard to diagnose sometimes.

An engine no-crank condition can be hard to diagnose sometimes.

Engine Not Turning Over?

The engine not turning over is a common engine performance problem. The root cause may range from a loose wire to a more serious mechanical issue. Fortunately, most of the problems that may prevent your engine from turning are possible to diagnose at home. Others are more difficult; for example, when dealing with an electrical short or a component you wouldn't think could affect the starting system.

Thus, you can soon hit a roadblock trying to repair the starting system without knowing what to do next, while missing important clues. The purpose of this guide is to help you find those clues so you can follow the path that will most likely lead you to the source of the problem.

Let's see how you can speed up your diagnostic process.


WARNING: Your Oil Pressure May Be Low

How to Use This Guide

I. I Hear the Starter Motor Rotating

II. My Starter Makes a Noise

A) I Hear a Click Sound

B) I Hear a Chattering Sound

C) I Hear a Grinding Noise

III. I Don't Hear Any Noises

Using Your Headlights as a Diagnostic Tool

Starting System Current Draw Test

Voltage Drop Test

Engine Seize Test

A starter motor will fail after miles of service.

A starter motor will fail after miles of service.

How to Use This Guide

Although the engine not turning over is obvious—since the crankshaft is not rotating—the symptoms may manifest in different ways depending on the source of the problem. For example, an undercharged battery will probably produce just a click or no click at all when you try to start the engine; on the other hand, a loose starter or problems with the flywheel will probably produce a screeching sound every time you try to start the engine.

So one of the first things to do to speed up the diagnostic process, and the fixing of the problem, is to gather as much information surrounding the issue so that you can narrow down the potential sources to the minimum.

This guide is divided into three main sections, plus three main tests referred to by one or more sections. The section headings describe general potential symptoms your starter may be producing. Some sections are further divided into more specific symptoms.

Identify the section heading that closer describes the symptoms your engine is showing and go over the steps under that section to help you troubleshoot your engine no-crank condition.

I. I Hear the Starter Motor Rotating

Often, when the starter motor seems to work fine but the engine doesn't turn over, the starter motor is at fault.

  • Failed starter overrunning clutch
  • Starter mechanism fails to engage pinion gear
  • Pinion gear teeth worn out or broken
  • Flywheel teeth worn out or broken

The overrunning clutch allows the pinion gear to only rotate in one direction to turn the flywheel; then, it lets the gear spin freely when the engine has reached running speed.

Remove the starter motor, and use a standard screwdriver to turn the pinion gear. It should turn in one direction only; check the gear teeth for wear and damage. Or take the starter motor to your local auto parts store. They can bench test the starter for you without charge.

If the starter motor turns out fine, check the flywheel for missing teeth or damage to the ring gear or similar problems. The Engine Seize Test section below describes a couple of methods you can use to turn the engine so you can check the flywheel ring gear, if necessary.

Make sure the battery terminals are clean and tight.

Make sure the battery terminals are clean and tight.

II. My Starter Makes a Noise

Clicking, chattering, and loud grinding noises, other than a regular starter motor operating, usually mean trouble in the starting system. The problem could lie with the starter motor itself, a component in the starter system, the connecting wires or the battery.

I Hear a Click Sound

A single, solid click sound usually means a problem with the starter motor, the starter solenoid, or a seized engine. You can remove the starter motor and take it to an auto parts store and have them test it. If the starter motor works fine, try turning the engine manually. Refer to the section below Engine Seize Test, which describes how you can turn the engine manually.

I Hear a Chattering Sound

  1. First, make sure that you have a charged, healthy battery. Even if you're reading above 12 DC volts from your battery with your multimeter, it doesn't mean it can deliver the required amps for the starting system to work. Take your battery to an auto parts store to have it checked, or check the battery yourself with a hydrometer.
  2. After checking the battery, visually inspect the starting system connections, at the battery terminals, at the starter solenoid or starter remote relay. Loose, corroded (white, greenish or blueish crud) or damaged connections will resist electrical flow and prevent the starter motor to function properly.
  3. If everything looks fine, do a Voltage Drop Test on the starting system connections as described in that section below. You may have a corroded or broken cable or wire. Follow that test with the Starting System Current Draw Test.

I Hear a Grinding Noise

A loud, chattering metallic noise usually means one of three things:

  • The starter motor mounting bolts are loose
  • The pinion gear is damaged
  • The ring gear around the flywheel is damaged.

Follow these diagnostic steps:

  1. Check and tighten the starter mounting bolts to the torque listed in your vehicle repair manual.
  2. If the starter motor bolts check OK, remove the starter and check the pinion gear.
  3. If the pinion gear seems in good shape, check the teeth at the flywheel ring gear for damage. You may need to use a flywheel turner or turn the crankshaft using a breaker bar to inspect the whole ring gear. Refer to the section Engine Seize Test below.
Use your headlights as a diagnostic tool.

Use your headlights as a diagnostic tool.

III. I Don't Hear Any Noises

Sometimes, the starter motor won't produce any sounds, not even a click, when you try to start the engine.

  • This could mean the pinion gear got stuck at the flywheel ring gear. With a manual transmission, it's easier to verify this. Set the transmission to gear and rock the vehicle a few times. Then try to start the engine. On an automatic transmission, hit (but don't damage or dent) the starter with a hammer or rubber mallet to rattle and unstuck the inside mechanism. Then try to start the engine.
  • It's possible you may have an electrical short or bad connection somewhere in the starting circuit. To start checking the circuit, if you turn the ignition key to the On position and you don't see the dashboard warning lights come on, but your headlights, radio, and other accessories work fine, look for a possible blown ignition circuit fuse. To find the fuse, look for a 'power' box under the hood, or behind a fuse panel cover under your dashboard (driver's side or passenger side). Also, check the ignition relay (check your repair manual for the location, then test the relay.

High resistance poses another problem for the starting system circuit. But this calls for some specific tests:

Using Your Headlights as a Troubleshooting Tool

  1. Turn on the headlights, windshield wipers and radio. If they fail to work, you may have a discharged or failed battery, or corroded battery terminals (white crud stuff around them), one or both battery terminals are loose, or the ground connection (the thin wire that runs from the black battery cable to the car body) is corroded or loose. Turn off the ignition, headlights, windshield wipers and radio. Once you've checked your battery and the connections, proceed to the next steps.
  2. Stand in front and to one side of your vehicle so that you can see the headlights clearly.
  3. Ask an assistant to turn on the headlights and try to start the engine while you observe the headlights.

If the headlights remain bright when your assistant tried to start the engine, check for a possible short in the starting circuit.

  • First, check the starter solenoid. If the starter solenoid on your starter sits on top of the motor, you can take the starter motor to your local auto parts store for a quick check.

Note: When testing the starter solenoid, if you don't detect voltage at the control circuit wire, probably your neutral safety switch (automatic transmission) needs an adjustment or has failed (newer vehicles now use a Transmission Range [TR] sensor instead and may set a trouble code in the computer memory when it fails); also, there could be a problem with the clutch interlock switch (manual transmission). Another possibility is an open at the wire connecting the fuse panel to the control circuit terminal at the solenoid, or an open or failed ignition switch.

  • Then, using a multimeter, check for battery voltage along the positive (red) battery cable. For this test, your battery has to be fully charged. If you don't own a digital multimeter, you can get an inexpensive one from your local auto parts store or online. It's an indispensable tool for automotive troubleshooting.
  1. Set your voltmeter to 15 or 20 DC volts. Then connect the black meter probe to the negative (-) battery post, and the red meter probe to the positive (+) battery post. You should read above 12 volts, otherwise, charge and have the battery checked at your local auto parts store.
  2. Leave the black meter probe connected to the negative side of the battery, and connect the red meter probe to the terminal connected to the positive side of the battery.
  3. Then, move the red probe to the next connecting point along the red battery cable, until you reach the terminal and connection at the starter motor.
  4. At every point along the battery cable, you should read battery voltage. Otherwise, check for an open or damaged cable or connection between the point where you found no battery voltage and your previous checkpoint.

If the headlight brightness dimmed when your assistant tried to start the engine:

  1. Check the battery cables at the battery terminals, solenoid or relay, and ground connections for corrosion, loose or broken wires.
  2. Make sure the starter is properly mounted, otherwise it won't be properly grounded and electric current won't reach the starter.
  3. Check voltage drop on the battery cable that connects to the starter motor as described in the section Voltage Drop Test below.
  4. If voltage drop is OK, go over the section Starting System Current Draw Test below.
  5. If your starter draws too much current but voltage drop is fine, either your starter has failed or your engine has a mechanical problem (you can take the starter motor first to your local auto parts store for a quick check if you prefer). Check to see if you can turn the engine manually. Refer to the section Engine Seize Test below.
  6. If the engine rotates smoothly without difficulty, replace the starter.

Some vehicle models, like the Chevy Silverado shown in the video below, have some common issues with the starting system.

Starting System Current Draw Test

You can perform a starter system battery current draw test yourself using an inductive pick-up meter. Consult the repair manual for your particular vehicle make and model, if necessary.

  1. For this test, disable the ignition system (unplug the ignition coil cable that connects to the distributor and connect it to ground using a jumper cable) or disable the fuel system (remove the fuel pump fuse).
  2. Connect the ammeter to the positive or negative battery cable (read the ammeter manufacturer instructions).
  3. Ask an assistant to try to start the engine for about ten seconds.
  4. On a 4-cylinder engine, a healthy starter motor will draw about 110 amps; in a 6 cylinder or small V8 engine you'll see the motor pulling about 200 amps; a large V8 engine will probably draw close to 250 amps. When amps differ much from what the manufacturer specifies check for problems with the starter motor, solenoid, connecting wires or cables.
A multimeter is an indispensable tool to diagnose starting system problems.

A multimeter is an indispensable tool to diagnose starting system problems.

Voltage Drop Test

  1. Set your multimeter to 15 or 20 Volts DC.
  2. Disable the ignition system (unplug and ground the ignition coil) or disable the fuel system (remove the fuel pump fuse) to prevent the engine from starting.
  3. Connect one meter probe to the connection you want to test (for example, a battery post), and connect the other voltmeter probe to the terminal that connects to that connection.
  4. Have an assistant try to start the engine for about 10 seconds or less.
  5. You should get no more than 0.1 to 0.3 volts at any connection along, for example, the battery path to the starter motor, if those are the connections you're testing.
  6. A voltage drop test between the battery positive terminal and the connection at the starter solenoid where the battery cable connects to should not go over 0.5 volts.
  7. Any reading above those indicated above means a problem with that connection. Make sure the connection is clean and tight, and that the wire or cable is not broken or filled with corrosion at the terminals.

Engine Seize Test

Although not as common, mechanical problems can also prevent your engine from turning over. The easiest way to check whether your engine has seized is to manually turn the engine. To turn the engine, you have two alternative methods: You can use either a flywheel turner or a breaker bar. Let's check the former method first.

Using a Flywheel Turner

  1. Remove the bell housing cover to gain access to the flywheel. On some models, you can access this cover from above the engine compartment. On other models, you'll need to raise your car on jack stands to reach the cover from underneath.
  2. Block the rear wheels to prevent the car from rolling.
  3. Set the transmission to Neutral and engage the parking brake.
  4. After removing the access cover, turn the flywheel with the tool.

Using a Breaker Bar

Another option is to use a breaker bar and the appropriate socket size to turn the crankshaft. You do this by turning the large, center bolt that holds the crankshaft pulley at the front, lower side of the engine.

  1. Raise and safely secure the car on jack stands.
  2. Remove the passenger side front wheel.
  3. Block the rear wheels to prevent the car from rolling.
  4. Place the transmission in Neutral and engage the parking brake.
  5. Now try turning the crankshaft using the breaker bar, extension, and socket.
  6. If you can't turn the engine, or it's difficult to turn, you may have a mechanical problem.
  7. If you can turn the engine, but nothing turned wrong in your previous diagnostics, check the flywheel teeth for damage by removing the flywheel cover at the back of the engine and examine the ring gear as you turn the crankshaft.

Note: If you have difficulty turning the engine, remove the spark plugs (number the plugs and wires first so you can replace them in their correct place), then try turning the engine again. If you still can't turn the engine, or it's difficult to turn, you definitely have mechanical problems.

Find the Culprit

Starter system problems are common, and that includes no-crank issues. However, trying to find the culprit behind the fault can be tricky at times. This guide helps you get to the root of the problem by following a systematic approach. This will help you stand a better chance of repairing your car and getting back on the road faster.

This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.

Questions & Answers

Question: The engine will turn over fine when it’s cold but after running for a few minutes, the engine will not turn over when hot. It will sound like it’s going to turn over but fails to do so. Suggestions on what might be the problem?

Answer: There could be a problem with the starter itself, the battery or the starter circuit, including battery cable corrosion. Test the starter circuit for voltage drop first:

Then have the battery checked and the starter motor and solenoid. Also, the starter motor or solenoid may be absorbing too much heat during engine operation. If you try to start the car with a warmed engine, the hot starter or solenoid will have problems cranking over the engine. In this case, you need to install a heat shield to prevent the starter/solenoid from absorbing too much heat.

Question: I rebuilt my engine because I spun a bearing. So after I reassembled the engine I put the key in the ignition, turned it and the starter was cranking but I accidentally backed off the key. So I tried to start the car again nothing happens. I hear the relay, but I hear nothing coming from the starter. What could be the problem?

Answer: Make sure the battery is fully charged and voltage is getting to the starter. The problem could be with the starter solenoid, or the starter itself too. If the starter is worn, it might be too weak to crank a rebuilt engine.

Question: If you don't have a breaker bar, what else could you use to turn over the engine?

Answer: You may use a long tube instead, and a strong ratchet. But remove the spark plugs to make the engine easier to rotate.

Question: What kind of tool do you use to turn the flywheel?

Answer: You can do it by turning the bolt on the harmonic balancer in front of the engine using a breaker bar, or you can use a flywheel turning tool

Question: My engine has a new battery, new starter but won't crank nor turn over. What could it be?

Answer: Check the connections from the battery to the starter, specially ground. This other post will help you check the voltage drop in this circuit.

Question: If the engine turns but only 3/4 of the way, what could that be?

Answer: It depends. If the car has been sitting there for some time, rust may prevent one or more cylinders from going all the way up. A slipped timing belt can cause a piston to hit a valve; A stuck valve (valve train damage) can have the same result; a bad piston rod and other similar mechanical problems can also prevent a crankshaft from turning.

Question: In a 55 Ford V8, which way should you try to turn the engine clockwise or counter-clockwise?

Answer: I believe the engine turns clockwise -- if you stand in front. But this guide might help you double check:

Question: When I drove my 98 Rodeo 2.2l home, it took a couple of trips because it had a head gasket issue. I replaced the head gasket, as well as shaving the head. I put everything back together and turned the crank to align it for the timing as well as the camshaft. Now that I have everything on, it won't turn over. It's as if the motor has seized. I tried with a break bar and push start and nothing is working. Any advice?

Answer: Try removing all the spark plugs and see if you can turn the engine manually. If not, there could be several possibilities here. Let’s say that the head gasket problem caused coolant to get to the combustion chambers. Driving the car like that could cause some damage to valve train components or pistons, while the pistons were trying to compress coolant. If you ran the engine with very low oil or oil unable to lubricate critical components, it probably caused some damaged, and is preventing the crankshaft from turning. The other possibility is that the engine accumulated some rust during the time it took you to replace the head gasket and put everything back together. In this case, you may try removing all the spark plugs and pour some engine oil through the spark plug holes. Let the oil sink through the cylinder walls for three or more days. Then try to turn the engine with the breaker bar and see if it rotates.

Question: I had my 304 v8 rebuilt, stroked to 355. I put an engine in and a new twin plate clutch but now when I turn the key, the engine struggles to turn over. When I put my foot on the clutch, the engine turns over freely. Any ideas?

Answer: I'm assuming you live in Europe, since all models in USA come with a safety switch that won't let you start the engine unless you step on the clutch. You may have a worn starter motor. Not pressing the clutch, the motor has to turn the engine and gearbox. When you press the clutch, the motor only turns the crankshaft. So you might want to check the starter. Hope this helps.

Question: My truck won’t crank with plugs in, yet it cranks just fine with them out. How can I troubleshoot my truck's failure to crank?

Answer: Make sure the battery is fully charged and in good condition. Check the connections between the battery and starter, starter motor condition, and engine grounds. Ignition timing problems can also cause this.

Question: My 2004 Mazda Rx8 with a newish engine works perfectly in summer temperatures with no starting issues. As soon as it gets cooler, around 12c and below, the starter refuses to crank. The battery is fully charged and load tested. I can resolve it by warming the battery area with a fan heater for 30mins! There was no click from the motor but all dash lights come on. It will restart easily until allowed to cool down. Any ideas on this very frustrating problem?

Answer: I think this other post can help you. Especially, check out the last section:

Question: What do I do if my flywheel engages because the belt drive moves but engine doesn't turnover?

Answer: Check the timing belt. It probably jumped or broke (?). Do a compression test, if necessary.

Question: Replaced the starter, alternator, battery, and cleaned all ground wires and can turn motor. Starter engages but motor will not turn over? Voltage drops from 12.3 to 8?

Answer: Check the voltage drop on the starting circuit and engine grounds. You may be loosing voltage there. These other posts may help.