Why wont my crank turn over?

If your car's crank won't turn over, it could be due to a variety of issues, from a dead battery to a problem with the starter motor. In this article, we'll explore the common reasons why a crank might not turn over and provide some troubleshooting steps to help you get your car back on the road.

Potential Causes of a Non-Turning Crank

There are several possible reasons why your car's crank won't turn over:

• Dead Battery - A dead or weak battery is one of the most common reasons a crank won't turn over. The battery provides the necessary power to start the engine, and if it's not charged, the crank won't have enough juice to turn over.


• Starter Motor Failure - The starter motor is responsible for turning the engine over when you turn the key. If the starter motor is faulty, it won't be able to crank the engine.


• Ignition Switch Issue - The ignition switch is the component that sends the signal to the starter motor to engage when you turn the key. If the ignition switch is malfunctioning, it won't trigger the starter.


• Loose or Corroded Connections - Loose or corroded electrical connections in the starting system can prevent the necessary power from reaching the starter motor, causing the crank to not turn over.


• Mechanical Engine Issues - In some cases, the issue may be with the engine itself, such as a seized or damaged crankshaft, which would prevent the engine from turning over.

Determining the exact cause of the non-turning crank will require some troubleshooting, which we'll cover in the next section.

Troubleshooting Steps

To diagnose the reason your car's crank won't turn over, follow these troubleshooting steps:

1. Check the Battery - Use a voltmeter to test the battery's charge. If the battery is dead or low, you'll need to charge or replace it.


2. Test the Starter Motor - With the battery charged, try tapping the starter motor while someone else turns the key. If the starter engages, the issue may be with the ignition switch or wiring.


3. Inspect Electrical Connections - Check all the electrical connections in the starting system, including the battery terminals, starter connections, and ignition switch wiring. Tighten any loose connections and clean off any corrosion.


4. Listen for the Starter - When you turn the key, listen closely to see if you can hear the starter motor engaging. If you don't hear anything, the starter motor may be the issue.


5. Check for Mechanical Issues - If the electrical components all seem to be working, the problem may be mechanical, such as a seized engine or damaged crankshaft. In this case, you'll need to have a mechanic inspect the engine.

By following these troubleshooting steps, you should be able to identify the root cause of your car's non-turning crank and take the necessary steps to get it running again.

How to manually turn the crankshaft?

Wrench. Set it to the size of the crankshaft. Snout kind of snug it down and then as you rotate it's going to catch on the wood drift key. And you'll be able to turn the crank.

Can a blown fuse cause a crank no start?

A fuse can cause cranking without starting if it powers critical systems like the fuel pump or ignition coil. Check the fuse box for blown fuses related to these circuits. Inspect the fuel pump relay and ignition relay as well. If fuses and relays are intact, test the fuel pump operation and spark presence.

Why does my engine crank but not turn over?

An engine that cranks but won't start is likely experiencing a problem with the fuel or spark systems. Common causes include a bad fuel pump, clogged fuel filter, faulty spark plugs, or a bad crankshaft position sensor. Other possibilities are an empty fuel tank, low engine compression, or issues with the battery or alternator. 
Fuel system problems
This video demonstrates how to check the fuel pump: 1mEasyAutoFixYouTube · Sep 9, 2023

• Fuel pump: If the pump is bad, it won't send fuel to the engine. Listen for a soft hum from the gas tank area when you turn the key to the "on" position; if you don't hear it, the pump may be failing. 
• Fuel filter: A clogged filter can restrict fuel flow to the engine, even if the pump is working. 
• Empty fuel tank: This is the simplest cause; check your fuel gauge first. 
• Bad fuel: Old or contaminated fuel can prevent the engine from starting. 

Ignition and spark problems
This video explains how to test for spark: 57sScotty KilmerYouTube · Mar 30, 2010

• Spark plugs: Worn-out or fouled spark plugs will not create a strong enough spark to ignite the fuel. 
• Ignition coils: In modern cars, faulty ignition coils can prevent spark from reaching the plugs. 
• Crankshaft position sensor: This sensor tells the car's computer when to fire the spark plugs. A faulty sensor will cause a no-spark condition. 

Other potential issues

• Battery: While the engine cranks, a weak battery may not have enough power to start it. Check for dim headlights or a slow cranking sound. 
• Compression: A loss of compression, possibly from a blown head gasket or a jumped timing belt, can prevent the engine from starting. 
• Timing belt/chain: If the timing belt or chain has broken or slipped, the engine will not be able to start. 
• Sensors: Other failing sensors, like the camshaft position sensor, can provide the computer with incorrect data and prevent the engine from starting. 
• Anti-theft system: An improperly functioning anti-theft system can immobilize the engine. 

How to diagnose

1. Check for fuel: Try spraying a small amount of starting fluid into the air intake. If the engine starts briefly and then dies, you have a fuel problem. 
2. Check for spark: If the engine doesn't start with starting fluid, you likely have an ignition problem. A mechanic can check for spark at the plugs. 
3. Listen for the fuel pump: Turn the key to the "on" position (without cranking) and listen for a brief hum or whine from the fuel tank area. 
4. Check the battery: Make sure the battery terminals are clean and tight. A weak battery can cause both cranking and starting issues. 
5. Scan for trouble codes: Use an OBD-II scanner to check for any diagnostic trouble codes, which can provide valuable clues. 

How to tell if an engine has seized?

An engine is seized if it won't crank or turn over, which can be confirmed by manually trying to turn the crankshaft and finding it is completely stuck. Other common signs include unusual grinding or knocking noises, a strong burning smell, and a rapidly rising temperature gauge. A lack of oil or a recent overheating event are common causes. 
This video demonstrates how to check if an engine is seized: 34sMotorCarNutYouTube · Mar 14, 2023
Symptoms to look for

• No crank or "no-start": The most direct sign is when the key is turned, but the engine doesn't even attempt to turn over, or it makes a clicking or clunking sound and refuses to crank normally. 
• Sudden engine death while driving: If the engine stops running suddenly and is accompanied by a loud bang or clunk, it could indicate a catastrophic internal failure. 
• Overheating: A frequently overheating engine can lead to a seizure due to lack of lubrication from heat damage. 
• Burning smell: A strong, burning odor, often from oil or metal, indicates extreme heat from friction between seized components. 
• Warning lights: The "check engine" light or oil pressure light may come on, especially if the engine seized due to a lack of oil. 
• Unusual noises: A seized engine may make grinding or knocking noises when the starter is engaged because internal parts are grinding against each other. 

How to test for a seized engine 
You can watch this video to see how to test for a seized engine: 57sMegaMilesBenYouTube · Jan 15, 2023

1. Disconnect belts: First, remove the serpentine belt to rule out a seized accessory like the alternator or power steering pump. 
2. Try to turn the crankshaft: Use a socket and a breaker bar on the crankshaft pulley bolt and try to turn it clockwise by hand. 
3. Check for movement: If the crankshaft will not move or feels extremely stiff, the engine is seized. If it moves, it is not seized, and the issue lies elsewhere.