Diagnosing Crankshaft Position Sensor Clicking Sound During Left Turns

Hearing a clicking sound from your crankshaft position sensor area when you turn left is unsettling. You might wonder if something expensive is about to break, or if it's even safe to keep driving. This kind of noise is tricky because it only happens under a specific condition a left turn which makes it easy to dismiss and easy to misdiagnose. But ignoring it can lead to bigger problems down the road, from engine stalling to transmission damage. Learning how to diagnose this issue yourself saves you time, money, and the frustration of chasing the wrong problem at the shop.

Why Does a Crankshaft Position Sensor Click Only When Turning Left?

This is the first question most people ask, and the answer usually comes down to physics. When you turn left, the vehicle's weight shifts to the right side. This shift puts stress on engine mounts, wiring harnesses, and the sensor's mounting position. The crankshaft position sensor can click specifically during left turns because the engine rocks slightly on its mounts, changing the gap between the sensor and the reluctor ring. That small movement can cause the sensor housing to vibrate against the block, producing an audible click.

Another common cause is a loose or damaged wiring connector. As the engine shifts during a left turn, a frayed wire or a connector that isn't fully seated can make brief contact and then break away, creating a clicking or snapping sound that seems to come from the sensor area.

What Tools Do I Need to Diagnose This Problem?

You don't need a full shop setup. Here's what will help:

OBD-II scanner to check for stored or pending trouble codes related to the crankshaft position sensor (common codes: P0335, P0336, P0339)
Multimeter to test the sensor's resistance and voltage output
Flashlight to visually inspect the sensor, wiring, and connector
Jack and jack stands to safely access the underside of the engine if needed
Basic hand tools wrenches and sockets for removing the sensor if inspection requires it

If you don't already own an OBD-II scanner, something like the Innova brand offers affordable models that read crankshaft position sensor codes clearly.

How Do I Start the Diagnosis Step by Step?

Start simple and work your way deeper. Here's a practical sequence that experienced mechanics follow:

Scan for codes first. Plug in your OBD-II scanner and look for any crankshaft position sensor codes. Even if the check engine light isn't on, there may be pending codes that point you in the right direction.
Do a visual inspection. Locate the crankshaft position sensor (usually near the crankshaft pulley or the transmission bellhousing). Check for oil contamination, cracked housings, loose mounting bolts, or obvious wiring damage.
Wiggle test the wiring. With the engine idling, carefully wiggle the sensor's wiring harness and connector. If the engine stumbles, misfires, or you hear the click, you've likely found a wiring issue.
Simulate the left turn. Have someone turn the steering wheel fully to the left while you listen from the engine bay (safely, with the vehicle on stands or in a controlled environment). Try to pinpoint exactly where the sound originates.
Test the sensor with a multimeter. Disconnect the sensor and measure its resistance. Compare your reading to the manufacturer's spec, which you can find in a mechanic-level troubleshooting guide. A sensor reading outside spec needs replacement.
Check engine mounts. Worn or broken engine mounts let the engine rock excessively during turns. This extra movement can cause the sensor or its wiring to make contact with surrounding components, producing a click.

Could It Be Something Other Than the Crankshaft Position Sensor?

Absolutely. This is one of the most common mistakes people make zeroing in on the crankshaft position sensor without ruling out other possibilities. Here are some look-alike culprits:

CV joint or axle noise A worn CV joint often clicks during turns, and the sound can carry through the engine bay, mimicking a sensor issue.
Loose heat shield A heat shield near the crankshaft area can rattle or click when the engine shifts during a turn.
Starter motor solenoid A failing starter solenoid can click in certain positions, and engine movement during a turn can trigger it.
Serpentine belt tensioner A worn tensioner can click or knock when load shifts during a turn.

Understanding the full range of causes behind clicking noises when turning left helps you avoid replacing a perfectly good sensor.

What Are the Signs That the Sensor Itself Is Failing?

A clicking sound during left turns is just one clue. Look for these additional symptoms that suggest the crankshaft position sensor is going bad:

Intermittent engine stalling, especially at low speeds or idle
Rough idle or misfires that come and go
Hard starting or no-start conditions the engine cranks but won't fire
Check engine light with codes P0335 through P0339
Erratic tachometer readings while driving

If you're hearing the click during left turns and experiencing one or more of these symptoms, the sensor is very likely the problem.

What Mistakes Should I Avoid During Diagnosis?

Here are errors that waste time and money:

Replacing the sensor without testing it. A new sensor costs $15–$80, but if the real problem is a wiring issue or a bad engine mount, you've wasted effort and still have the noise.
Ignoring the connector. The click might come from a connector that's partially unplugged or corroded, not from the sensor body itself.
Overlooking engine mounts. This is the most overlooked cause. Worn mounts let the entire engine shift during turns, creating multiple noise sources.
Driving with the problem too long. If the sensor truly is failing, the engine can stall without warning a safety issue, especially in traffic.

When Should I Just Take It to a Mechanic?

If you've run through the basic diagnosis steps and can't isolate the noise, or if the vehicle is also stalling or misfiring, it's time for a professional. A shop with a lift and a lab scope can test the sensor's signal pattern in real time, which reveals problems a multimeter can't catch. Be specific when you describe the issue tell them it clicks only during left turns. That detail alone can save diagnostic time.

Quick Diagnostic Checklist

☐ Scan for OBD-II codes (P0335–P0339)
☐ Visually inspect the sensor, wiring, and connector
☐ Perform a wiggle test on the harness with the engine running
☐ Simulate a left turn and listen for the click
☐ Test sensor resistance with a multimeter against manufacturer specs
☐ Check engine mounts for excessive play or visible damage
☐ Rule out CV joint, heat shield, and tensioner noise

Next step: If your scan reveals a crankshaft code and the wiggle test reproduces the click, replace the sensor and its connector. If there's no code and no wiggle response, focus your attention on the engine mounts and surrounding hardware. Start with the simplest check a visual and physical inspection before spending money on parts. Try It Free