How To Start a Car with a Bad Crankshaft Sensor: Proper Way

How to start a car with a bad crankshaft sensor can be accomplished with various methods; namely, start in neutral, cycle the key in the ignition, or use starting fluid. Sometimes, you may require replacing the part altogether.

How To Start a Car with a Bad Crankshaft Sensor

This article has discussed this in detail, including the simple DIY steps to replace a crankshaft sensor. Before the end of this guide, you’ll also discover the tell-tale symptoms of a failing crank sensor so you can act on time and avoid inconveniencing situations, such as engine failure.

How To Turn on a Car with a Failing Crankshaft Sensor?

To turn on a car with a failing crankshaft sensor, start in neutral gear. If that doesn’t work, try to cycle the key in the ignition. Alternatively, open the hood and spray a small amount of starting fluid inside the air intake.

As you can already guess, the crankshaft position sensor (CKP sensor) is affixed near the engine’s crankshaft. How does it work? The position sensor works under a simple principle; it comprises a wire coil and magnet.

While the engine is running, the crankshaft also spins. That spinning motion generates some electrical current in the wire coil, and the strength of the current depends on the crankshaft speed.

The engine control module (ECM) utilizes the electrical signal to determine the position and rotation of the crankshaft. It then uses that data to time the ignition and fuel injection processes accurately. Thus, the sensor is a critical component of the engine. If it fails, it can trigger severe engine performance issues.

Some have asked, “Can a crankshaft sensor cause a car to stall?” or “Will a car crank with a bad crankshaft sensor?” Well, a faulty CKP sensor can cause not only stalling but also misfiring and ruined fuel economy. In the worst-case scenario, it’s quite likely that your car won’t start!

But, depending on the extent of the problem, the above tricks can help you to get the vehicle started so you can at least drive it to the repair shop. See more in detail.

  • Try Starting in Neutral

Starting the car in neutral can bypass the sensor and let the engine start. Neutral means that zero power is transmitted from the engine to the wheels. Although the neutral gear is rarely used, it helps during mechanical failure. For example, when the pedals suddenly stop working.

Additionally, moving the gear stick to the neutral position when you have a defective crankshaft sensor can help the car start. That’s especially if the transmission is the one causing the sensor malfunction.

  • Cycle Your Ignition Key

First, address possible issues that could prevent your car from starting. For instance, check the fuel level and ensure the tank has enough fuel. Also, take the battery cables out and clean any build-up of dirt, and correction on the terminals and connections. And remember to check if there are loose wires near the sensor and tighten them to prevent an electrical short.

Car Ignition Key

It would also help to locate the spark plugs and ensure they are clean, as they are on the list of what causes crankshaft sensor to go bad. Use a wire brush to remove any dirt and debris on them.

After that, insert your car key into the ignition and turn it to the “ON” position, then let it sit for a few seconds. Next, please turn it off and repeat the steps severally to help prime the fuel system and probably facilitate the engine’s start.

  • Use Starting Fluid

The fluid is a volatile chemical (usually heptane, diethyl ether, and carbon dioxide) normally packaged in pressurized spray cans. It’s formulated to help start car engines with difficulty starting due to cold weather or low battery power.

But if you can’t start your car and suspect an issue with the sensor, use it to aid the process. It’s only a temporary fix for crankshaft position sensor and shouldn’t be used more than a few times (only when necessary). Note that the product is highly combustible and can cause your engine to catch fire if used carelessly.

To use the fluid properly, open the car hood and find the air intake (behind the front grille). Once you locate it, remove the cap and spray a small amount of the fluid into it. Replace the cap and try starting the engine.

If your engine starts after implementing one or more of the above methods, take it to a specialist as soon as possible. How long can you drive with a bad crankshaft sensor? You shouldn’t drive farther than to the repair shop because it can be dangerous. You would be putting the engine at risk of serious damage.

A qualified mechanic can diagnose and offer a suitable solution. For those who want to know how to bypass crank position sensor, it’s not recommended, as it’s a temporary fix and can cause other engine malfunctions in the long run.

Generally, you would need to cut and connect the wires in the sensor to change how it transfers electrical signals to the engine’s onboard computer. The steps required to bypass crankshaft sensors vary from one car model to another. Therefore, that’s something that only professionals should handle.

The best way to save time and effort and get the problem solved for good is to replace the part. On average, you can expect to pay $185 for a sensor replacement. You can spend less if you do it yourself. The procedure is usually straightforward as described in our next section.

How To Replace a Bad Crankshaft Position Sensor On Your Car?

To replace a bad crankshaft position sensor on your car, disconnect the battery and locate the bad crank sensor. Once you find the sensor, remove it and clean the area around the mount. Now plug in the new sensor, then start the car to test it.

  • Disconnect the Battery and Locate the Sensor

First (assuming you’ve already bought a new and the correct sensor for your vehicle), you must cut off the power supply to prevent electrical shorts during the procedure. So, open the hood and remove the negative battery terminal using a wrench or pliers.

Disconnecting Car Battery

After that, locate the faulty crankshaft position sensor. Note that the crankshaft location varies, depending on the car model. But mostly, the component is close to the crankshaft. You’ll probably find it near the engine’s timing cover or harmonic balancer.

  • Take the Sensor Out

Once you’ve found the sensor, unplug its electrical connector. Next, remove the mounting bolts, then pull the sensor off its mount. Clean the area around the sensor mount to ensure a proper seal when you install the new sensor.

  • Install and Test the New Sensor

Plug the new sensor into the mount and replace the mounting bolts. Reconnect the sensor’s electrical connector and start the car to test the new sensor. If the engine starts, you’ve successfully replaced your defective crankshaft position sensor.

But if the vehicle doesn’t crank, there may be another problem. At this point, you’ll require the help of a specialist for further diagnosis and repair.

How To Know Whether Your Crank Position Sensor Is Failing?

To know whether your crank position sensor is failing, observe the common symptoms of a bad crankshaft sensor. They include the check engine light, extreme vibrations, and decreased accelerating power. As the problem progresses, you’ll probably notice ruined fuel economy, engine misfiring, stalling, and failure to start.

  • Check Engine Light

The check engine light (CEL) illuminates your dashboard whenever the ECU detects an issue with the engine. The sensor is in constant contact with the ECU. When the sensor malfunctions, it will send inaccurate data about the crankshaft’s position and speed. As a result, the engine will experience functional problems, triggering the CEL with a couple of DTC codes: P0335 and P0336.

  • Extreme Engine Vibration

When driving with bad crankshaft position sensor, you’ll probably feel an unusual vibration as you grip your steering wheel. As mentioned, a defective sensor cannot send accurate communication regarding the position and speed of the crankshaft.

Extreme Car Engine Vibration

The vibrations and rattling experience in your car’s hood result from the disagreeable speeds between the engine and crankshaft.

  • Decreased Performance

Since the ECU won’t know the correct crankshaft’s position, its ability to keep up with smooth engine operation will be significantly compromised. You may notice a delay in acceleration or power loss occasionally. The engine may also sputter when you accelerate, indicating that the crankshaft is struggling to compensate for some inconsistencies in the engine block.

  • Engine Misfiring

A bad crank sensor can cause your engine to sound like it’s popping and banging, especially when starting it. The misfiring will result from having too much fuel or needing more inside one or more cylinders.

  • Engine Stalling and Starting Problems

When the crank position detector fails, the engine and crankshaft gradually go out of sync. Eventually, the ECU may be unable to get the right amount of fuel-air mixture needed to keep the engine running. If the problem advances, you must replace the sensor because the engine won’t start.

  • Increased Fuel Consumption

As your crankshaft sensor starts to fail, you may experience increased fuel consumption. The ruined fuel economy is due to the engine running less efficiently. Note that most of these symptoms can also indicate another problem.

For example, a bad camshaft position sensor or spark plug can cause misfiring and increased fuel usage. It’s, therefore, essential to have the problem diagnosed and fixed as soon as possible to prevent costly damages. You can run a crankshaft sensor continuity and resistance tests using a multimeter to know whether it’s faulty.

Increased Car Fuel Consumption

Set the multimeter to the “ohm” (Ω symbol) settings to test for continuity. Next, touch the meter’s probes to the sensor’s terminals. You should see a reading or hear a beep. Otherwise, the sensor is defective and requires a replacement.

Next, with the multimeter still on “ohm” settings, touch its probes to the sensor’s terminals and take the readings. Your sensor is okay if the multimeter reads about 1,000 ohms. A lower or too high reading indicates that the sensor is faulty and must be replaced.

FAQs

– Does an Engine Need a Crankshaft Sensor?

Yes, an engine needs a crankshaft sensor to function correctly. Driving without or with a faulty sensor can cause serious engine malfunctions, such as greater fuel usage, reduced performance, and lead to engine failure. Please don’t try to bypass the sensor if it’s faulty; instead, have it replaced immediately.

– How Long Should a Crankshaft Sensor Last?

A crankshaft sensor should last at least 200,000 miles or a vehicle’s entire life. However, sometimes that doesn’t happen as the component is subjected to much strain and wear. A crankshaft sensor can fail for various reasons, including physical damage and wiring issues.

– Will Starting Fluid Cause a Car Engine to Stall?

No, starting fluid will not cause a car engine to stall unless you inject it in excess. The fluid must be used sparingly and only when necessary (e.g., battery power is too low). Improper use of starter fluid can flood the engine and ignite fire as it’s highly flammable!

Can a Car Start with a Bad Crankshaft Sensor?

A car starting without oil can be a challenging situation, but a bad crankshaft sensor is an entirely separate issue. The crankshaft sensor plays a crucial role in determining the engine’s position, so if it fails, the car may not start at all. However, this problem is independent of the oil level. It’s essential to address both issues separately for a smooth-running vehicle.

Conclusion

After reading our comprehensive guide above, you know how to start a car with a bad crankshaft sensor.

We will leave you with a summary:

  • It’s difficult to start an engine with a bad crankshaft sensor, but it’s possible.
  • You can try a few methods, which include starting in neutral, cycling your key in the ignition, and using starting fluid.
  • Driving with a faulty CKP or camshaft sensor is dangerous, and you should repair the problem as soon as you start the vehicle.
  • A replacement, which you can do yourself, is the best way to repair a defective crank position sensor.

Information is power, and now you have it in your hands. So, use it and get your car moving or contact a mechanic for further assistance.

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