Sierra 18-7556
Sierra 18-7556 — Product description
Sierra 18-7556 Crankshaft Position Sensor - Essential Engine Management Component
Ensure reliable engine performance and eliminate misfires with the Sierra 18-7556 Crankshaft Position Sensor. Designed for MerCruiser 5.0L and 6.2L fuel-injected engines, this precision sensor provides critical timing information to the engine control module for optimal ignition timing and fuel delivery.
Key Features & Benefits
- OEM Replacement Quality - Direct replacement for MerCruiser 864297001 and related part numbers
- Precision Signal Output - Accurate crankshaft position detection for optimal engine timing
- Marine-Grade Construction - Built to withstand harsh marine environments and temperature extremes
- Composite Cover Compatible - Specifically designed for engines with composite timing covers
- Plug-and-Play Installation - Direct connector fitment for straightforward replacement
- Enhanced Reliability - Eliminates engine misfires and performance issues
Technical Specifications
| Manufacturer: | Sierra Engine Parts |
| Part Number: | 18-7556 |
| UPC Code: | 808282340834 |
| Sensor Type: | Magnetic Crankshaft Position Sensor |
| Signal Type: | Variable Reluctance |
| Application: | Fuel-Injected Marine Engines |
Engine Compatibility
Direct Replacement For:
- MerCruiser 864297
- MerCruiser 864297001
- MerCruiser 864297T01
- Indmar 556293
- Volvo 3858979
- Mallory 9-298820
- Marine Power 464228
Compatible Engine Applications:
- MerCruiser 5.0L MPI (1998-2010)
- MerCruiser 6.2L MPI (1998-2010)
- MerCruiser 5.7L Fuel Injected
- MerCruiser 350 MAG
- MerCruiser 525 EFI
- Various GM V8 Marine Engines with Composite Timing Covers
Important: Only fits engines with composite (plastic) timing covers - NOT compatible with metal timing covers
Installation & Service
Installation Requirements:
- Verify engine has composite timing cover before ordering
- Disconnect battery before beginning work
- Remove engine cover to access sensor location
- Disconnect electrical connector from old sensor
- Remove sensor mounting bolt and extract sensor
- Install new sensor with proper torque specifications
- Reconnect electrical connector ensuring secure fit
- Clear any stored diagnostic codes after installation
Why Choose Sierra Engine Sensors?
Sierra Marine has been manufacturing premium engine management components for over 40 years. Their crankshaft position sensors are engineered to meet or exceed OEM specifications, using advanced magnetic technology that provides accurate signal output in demanding marine environments. Each sensor undergoes rigorous testing to ensure reliable performance and longevity.
Signs You Need This Sensor
- Engine misfires or rough running
- Intermittent stalling or no-start conditions
- Check engine light activation
- Poor acceleration or loss of power
- Engine beeping or alarm activation
- Diagnostic codes related to crankshaft position
Critical Engine Function
The crankshaft position sensor serves essential functions:
- Ignition Timing - Provides ECM with precise crankshaft position for optimal spark timing
- Fuel Injection Timing - Controls fuel injector pulse timing for efficient combustion
- Engine Speed Monitoring - Measures RPM for engine management calculations
- Misfire Detection - Enables ECM to detect and correct engine misfires
- Starting System - Critical for engine start-up and initial timing
Diagnostic Capabilities
Common Diagnostic Trouble Codes:
- P0335 - Crankshaft Position Sensor Circuit Malfunction
- P0336 - Crankshaft Position Sensor Range/Performance
- P0385 - Crankshaft Position Sensor B Circuit Malfunction
- Related misfire codes (P0300-P0308)
Performance Benefits
A functioning crankshaft position sensor ensures:
- Smooth Engine Operation - Eliminates misfires and rough idling
- Optimal Fuel Economy - Precise timing reduces fuel consumption
- Enhanced Power Output - Proper timing maximizes engine performance
- Reduced Emissions - Accurate fuel delivery improves combustion efficiency
- Reliable Starting - Consistent signal enables dependable engine starts
Frequently Asked Questions
How do I know if my timing cover is composite or metal?
Composite timing covers are made of black plastic material, while metal covers are aluminum or steel. This sensor only fits engines with composite (plastic) timing covers.
What are the symptoms of a failing crankshaft position sensor?
Common symptoms include engine misfires, rough running, stalling, check engine light, poor acceleration, and intermittent no-start conditions.
Can I test the sensor before replacement?
Yes, the sensor can be tested with a digital multimeter or oscilloscope. However, intermittent failures may require replacement for reliable diagnosis.
Do I need to clear codes after installation?
Yes, clear any stored diagnostic trouble codes after sensor replacement and test drive to ensure proper operation and no code recurrence.
Will this sensor work on my specific engine year?
This sensor fits 5.0L and 6.2L MerCruiser engines from 1998-2010 with composite timing covers. Verify your engine specifications and part number for exact compatibility.
Warranty & Support
Sierra Marine Parts are backed by manufacturer warranty against defects in materials and workmanship. Professional installation and proper diagnostic procedures ensure optimal performance and system reliability.
SKU: NVN-4004155
MPN: 18-7556
UPC: 808282340834
Technical specifications
| Brand | Sierra Engine Parts |
| Model | Sierra 18-7556 |
| SKU / MFR# | 4004155 |
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