What Causes Crankshaft Sensor To Go Bad? A crankshaft sensor is an electrical device that monitors the position or rotational speed of the crankshaft in an internal combustion engine, both petrol and diesel. Engine management systems employ this information to govern fuel injection, ignition system timing, and other engine characteristics. On petrol engines, the distributor had to be manually set to a timing mark before electronic crank sensors were available.
The crank sensor can be used in conjunction with a camshaft position sensor to monitor the engine’s piston-valve relationship, which is especially significant in engines with variable valve timing. This procedure is also used to “synchronize” a four-stroke engine when it first starts, allowing the management system to determine when to inject gasoline. It is also widely used to determine engine speed in revolutions per minute.
The main crank pulley, the flywheel, the camshaft, and the crankshaft itself are all common mounting points. This sensor, together with the camshaft position sensor, is one of the two most critical sensors in modern engines. Because the crank sensor position signal is used to time the fuel injection (diesel engines) or spark ignition (petrol engines), a failed sensor will cause the engine to not start or cut out while running. This sensor also provides speed information to the engine speed indicator.
Read also: Water In Gas Tank: How To Get Rid Of It
What Does a Crankshaft Sensor Do?
Whether inductive, Hall Effect, magnetoresistive, or optical crankshaft position sensors are used in current automobiles, they all serve the same objective. The primary function of a CKP is to keep track of the exact location of the crank and to measure the speed at which it rotates.
Furthermore, the Powertrain Control Module gets the data collected by the CKP and uses it to decide ignition timing or regulate the fuel injection process. The teeth of the reluctor ring attached to the crank pass near the sensor’s tip, generating a pulsed voltage signal that the sensor picks up and sends to the PCM. The PCM then uses this information to calculate when a spark should be generated for each cylinder.
The PCM will not create a spark or transmit fuel to the injectors if the crankshaft position sensor does not send a signal for one or more cylinders.
Symptoms of a Bad Crankshaft Sensor
The following are the common symptoms of a bad crankshaft position sensor. If you notice any of these signs, you know it’s time to fix or replace your crankshaft position sensor.
Check Engine Light Illuminates
Your check engine light turning on is one of the most prevalent signs of a malfunctioning crankshaft position sensor. After all, the function of light is to alert you when something is amiss behind the hood so you can address it. When your check engine light illuminates, you should get your engine inspected by a professional, regardless of whether it’s a crankshaft position sensor issue.
Hard Starting Of Vehicle
Another major red sign is your vehicle’s inability to start. Your crankshaft position sensor begins monitoring the position and speed of the crankshaft as soon as you try to start your car. If this sensor has a fault, it may not start the procedure, and the engine will not start as a result.
Backfiring Or Vehicle Stalling
A issue with your crankshaft position sensor can cause your car to stall and/or backfire, similar to the symptom mentioned above. The disruption of the crankshaft signal might cause the engine to stop off, therefore stalling is more common than backfiring. However, depending on how long the signal is out and how fast you’re going at the moment, backfiring may occur.
Your Engine Vibrates
Vibrations originating from the engine are one last indicator of a malfunctioning crankshaft position sensor. When the engine is running, some people believe there is a slight vibration from beneath the hood. If you observe a sudden rise in vibration, it could be due to an issue with the crankshaft position sensor. This vibration is frequently accompanied by a significant reduction in fuel economy and power. To get where you need to go, you’ll need significantly more power and gas.
What Is Crankshaft Sensor Replacement Cost?
Crankshaft position sensors cost between $120 and $300 to repair. The part will cost between $75 and $120 on its own. Labor costs will range from $45 and $180.
You must also account for the expected taxes and other charges that will be added to the total. In the end, getting this replacement job done won’t be prohibitively expensive. It’s well worth the money because you’ll be safeguarding your engine’s functionality.
What Is Crankshaft Sensor Location?
The crankshaft sensor is normally found in the front of the engine, around the bottom of the block. Most of the time, it’s hidden beneath the harmonic balancer. The crankshaft sensor can sometimes be found behind the timing cover, near the bottom of the block, but this is uncommon. It’s quite simple to replace the sensor as long as it’s on the outside of the block.
What Makes a Crankshaft Sensor Go Bad?
Excess Heat
Excessive heat in an engine can cause a variety of issues. If your engine generates too much heat as a result of inadequate lubrication, ventilation, or radiator issues, the heat can build up to dangerous levels, melting or cracking the crank sensor’s plastic case. Because the sensor is unable to communicate crankshaft information to the computer, the automobile will not start.
Faulty Or Wrong Wiring
The most typical cause of crank sensor failure is a faulty wiring harness. This can be caused by issues with the voltage, ground, or return circuit. Loose wiring, oil, and dirt can wear down the wiring harness, resulting in voltage disturbance or wiring wear and tear. As a result, the sensor may fail repeatedly. If this is the case, your vehicle may start but not stay started.
Timing Belt Damage
The timing belt can wrap around the crankshaft and damage several minor parts and sensors if it was broken in a collision or snapped due to normal wear and tear. When the timing belt snapped, the crank sensor may have been damaged. The wiring harness and the sensor may be harmed as a result of this. Even if the belt has been replaced, the sensor may be broken, causing your car to crank but not stay started after a few minutes.
How To Start a Car With a Bad Crankshaft Sensor
The severity of the damage determines whether or not you will be able to start a car with a defective crankshaft position sensor. If you can’t reach a mechanic any other way, you should only try to start a car with a bad crankshaft sensor. Furthermore, even if you follow each step exactly, there is no guarantee that your car’s engine will start.
To start a car with a defective CKP sensor, you’ll also need a starting fluid, so find the sensor and remove the sensor plug once you’re set. Apply the fluid and then attempt to start your vehicle. If the engine starts and then stops, you may have an issue with the vehicle’s fuel pump, which means the engine isn’t getting enough fuel. If you can’t get the car started at all, you should check the spark plugs.
In most cases, though, if the CKP sensor is malfunctioning, you won’t be able to start your car at all, and you’ll need to replace it before you can use it again.
