6 Symptoms of a Bad Crankshaft Position Sensor (and Replacement Cost)

Last Updated on September 7, 2021

In this article, we will go over one of the important sensors in the engine, commonly referred to as the “crankshaft position sensor”. Afterwards, you’ll understand its basic function, working principle, failure symptoms, and the replacement cost of this sensor.

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How a Crankshaft Position Sensor Works

The internal combustion engine depends on the crankshaft for its rotational energy. The main function of the crankshaft is to convert reciprocating energy (also known as linear energy) into rotational energy.

The latter will then give power to the wheels of the drivetrain below the car. This is how the wheels can spin forward and allow the vehicle to move in that direction.

As for the crankshaft position sensor, this simply detects how fast the crankshaft is spinning. Once it detects the spinning rate, it sends this information to the engine control unit of the vehicle.

This information will determine how the engine control unit regulates the timing of the fuel injection system and ignition system. You need the timing to be just right for the engine to produce the proper amount of power.

crankshaft position sensor replacement cost

The crankshaft position tells the engine control unit all it needs to know. You see, the crankshaft uses a timing chain, gearwheels, and a belt with teeth to drive the camshaft. The engine depends on the camshaft to operate the exhaust valves at the appropriate times.

If they don’t open and close correctly, it creates problems with the exhaust system. This all links back to the functionality of the crankshaft.

Therefore, the engine control unit will know the position of the crankshaft through the crankshaft position sensor. By judging the speed of the crankshaft in conjunction with its position, it will know the status of the camshaft’s functionality too.

Top 6 Bad Crankshaft Position Sensor Symptoms

An internal combustion engine must have a functional crankshaft position sensor. Otherwise, the engine control unit won’t receive accurate information about the position and speed of the crankshaft.

This will cause all sorts of problems with the functionality of the engine and the car’s driving performance. You will surely recognize these symptoms as they become present.

Below are the top 6 symptoms of a faulty crankshaft position sensor.

#1 – Engine Vibrations

steering wheel shakes

Are there vibrations coming from your engine? When you have a bad crankshaft position sensor, that means the engine control unit cannot manage the crankshaft properly.

As a result of this, your engine will vibrate quite extensively. You may even feel these vibrations sinking into the steering wheel as you hold it with your hands.

#2 – Check Engine Light

check engine light

The engine control unit stays in constant communication with the crankshaft position sensor. If there is ever something wrong with the sensor, then the computer will receive improper information regarding the speed of the crankshaft and its position.

This will cause functionality problems with the engine, resulting in the Check Engine warning light activating on the dashboard. In fact, this should be one of the first symptoms of a bad crankshaft position sensor. P0335 is a common code that may be displayed.

Related: P0016, P0017, P1345 (Crankshaft/Camshaft Position Sensor Correlation)

#3 – Weak Engine Performance

ambient light sensor

With a bad crankshaft position sensor, your engine control unit won’t know the correct position of the crankshaft or cylinders. This will cause a delay in the control unit’s ability to sustain the operation and performance of the engine.

During this delay, there will be moments of hesitation each time you step on the gas pedal a little bit harder. Sometimes it won’t respond at all. This can be very dangerous on a road that requires you to go faster without hesitation.

#4 – Trouble Starting Car

The engine control unit will be notified when the crankshaft position sensor is having problems. It is given a special malfunction code from the sensor which indicates there is some kind of problem with its functionality.

When you attempt to start your vehicle as this trouble present, it will be more difficult to get the engine going. If the problem continues without being resolved, you may not be able to start your engine at all.

#5 – Engine Stalling

rough engine idle

You may be driving along one day and have your engine suddenly stop running. This is engine stalling and it can happen quite frequently when you have a bad crankshaft position sensor.

If you don’t replace this sensor soon, your engine will eventually stop working altogether. Then you will have no choice but to get your vehicle towed to a mechanic, so the sensor can be replaced.

#6 – Cylinder Misfiring

cylinder misfire causes

A crankshaft position sensor that fails will not be able to accurately transmit data regarding the piston position to the engine control unit. This often results in a misfire inside one or more of the chamber cylinders.

Sometimes a bad spark plug can do this too but if you are experiencing any of these other symptoms, don’t rule out the possibility of a bad crankshaft position sensor.

Read also: Oxygen Sensor: Basic Function, Failure Symptoms and Replacement Cost

Crankshaft Position Sensor Replacement Cost

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If you experience at least two or more of the above symptoms, then you probably have a bad crankshaft position sensor. The only way to know for sure is to bring your vehicle to a licensed mechanic and have them diagnose the problem for you.

Once they have verified that it is the crankshaft position sensor causing the problem, then you can proceed to have the sensor replaced.

The replacement cost of the crankshaft position sensor is anywhere from $120 to $300. The cost of the part itself will be around $75 to $120. The cost of the labor will be anywhere from $45 to $180.

You need to factor in the estimated taxes and other fees that will be added to the total amount as well. In the end, this won’t be a terribly expensive replacement job to get done. It is worth the investment because you are protecting the functionality of your engine.


8 thoughts on “6 Symptoms of a Bad Crankshaft Position Sensor (and Replacement Cost)”

  1. I have to use the emergency brake for park. The gear shifter is all over the place and have to start the engine in neutral. Still from left to right but have no light telling me what gear I am in. Drive is either down low and will not go into park. I have problems finding drive and try not to go to a too low gear in drive. can you help me know what is wrong and what part #it is? Also where to locate. Auto store said could not find it, or order it. The car is a 2002 buick century.


  3. My 05 Durango 4.7 L engine jerks when reaching 2,500 rpm’s I can slightly let up on gas trans shift n runs fine till next 2,500 rpm’s friend says crankshaft position sensor needs replaced is this really prob before I buy parts I don’t need hope sumone can help thx

  4. 1995 Chevy Tahoe stalled on highway cranks and sometimes fires but will not turn over.

    Check engine light did appear when I hit 55mph

    • By “not turn over” do you mean it won’t start? Turning over usually means the engine crankshaft will freely rotate, but doesn’t necessarily mean the car will run.

      There could be a number of causes. You’ll have to check for air, fuel and spark to narrow down the problem.


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