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Estimates last updated June 18, 2026

2008 Mercury Mariner Camshaft Position Sensor Replacement Cost

The average cost for a 2008 Mercury Mariner Camshaft Position Sensor Replacement is between $105 and $146.

Labor costs are estimated between $37 and $54 while parts are priced between $68 and $92.
This range does not include taxes and fees, and does not factor in your unique location. Related repairs may also be needed.
For a more accurate estimate based on your location, use our Fair Price Estimator below.

Camshaft Position Sensor Replacement

What is a camshaft position sensor?

The camshaft position sensor is an electrical component that sits close to the engine's camshaft. In monitors the position of the camshaft as it rotates, and sends information about this rotation to the engine control module (ECM), the engine's computer. This information is used to control ignition timing fuel injection.

How does the camshaft position sensor work?

As the camshaft spins, the camshaft position sensor magnetically reads its position. The sensor continually sends this information to the engine's computer for comparison with data from the crankshaft position sensor. When the two signals reach the computer, they must match. If they don't, the computer will believe that an engine timing problem is occurring, and adjust settings in order to protect the engine.

Here are a few common symptoms that can be caused by a defective camshaft position sensor: 1. Engine may shut off or die intermittently 2. Engine may misfire and/or hesitate on acceleration 3. Check Engine Light may illuminate with a code set for camshaft position sensor

Mercury Camshaft Position Sensor Replacement Cost Estimates

The average cost for a Camshaft Position Sensor Replacement is between $105 and $146 but can vary from car to car.

Mercury Grand Marquis

Mercury Mariner Camshaft Position Sensor Replacement Cost by Year

The average cost for a Mercury Mariner Camshaft Position Sensor Replacement is between $105 and $146 but can vary from car to car.

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Camshaft Position Sensor Replacement

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What is a camshaft position sensor?

How does the camshaft position sensor work?

What are the symptoms related to a bad camshaft position sensor?

When the computer senses the engine is out of time, it will turn on the check engine light. The engine may stall or even just fail to start. If the engine runs, it will run poorly and get bad fuel mileage.

Can I drive with a camshaft position sensor problem?

It's a bad idea to drive a vehicle with a failed camshaft or crankshaft position sensor — in fact, it's usually impossible.

How are camshaft position sensor issues diagnosed?

Using a scan tool, a mechanic can read where the computer believes the crankshaft and camshaft are, and compare that information to their actual position. If the reading is incorrect, the position sensor will be tested, and replaced if necessary.

A camshaft position sensor code isn't always triggered by a defective camshaft position sensor. It can be triggered by other issues, such as a worn timing belt or timing chain, or a defective ignition module, crank shaft position sensor, or mass air flow sensor.

How is a camshaft position sensor replaced?

Replacement of the camshaft position sensor is completed by disconnecting the electrical connector or connectors and unscrewing the sensor. If required, sealant will be applied before inserting the new sensor into the engine. Finally the electrical connector is connected, and the vehicle is tested to confirm the repair. There are two common locations for the camshaft position sensor: inside the timing cover and near or on the engine's valve cover.

After replacing the camshaft position sensor, the engine's computer will need to be recalibrated.

Always use a factory OEM camshaft position sensor and be sure to check for any relevant Technical Service Bulletins (TSB), necessary software updates, and re-calibration procedures.

RepairPal recommendations for camshaft position sensor issues

When replacing the camshaft position sensor, make sure there are no obvious oil or coolant leaks that could ruin the new sensor. High-quality sensors — preferably OEM parts — should be used, as lesser products will likely lead to a repeated repair. Also, the vehicle's timing belt should be inspected at this time. If the timing belt or timing chain has failed, it will need to be replaced.