Sierra 18-7677 Marine Knock Sensor for GM V-8 Engines

The Sierra 18-7677 Knock Sensor is a precision-engineered marine engine component designed to protect GM small block V-8 engines from damaging detonation and preignition. This sensor monitors engine vibrations and detects abnormal combustion, sending immediate signals to the engine control module (ECM) to adjust ignition timing and prevent potential engine damage.

Key Features:

• Fits GM V-8 engines (305, 350, and 377 CID) used in marine applications
• Detects engine knock and detonation to protect against abnormal combustion
• Single-wire plug-in design for straightforward installation
• Manufactured in the USA with high-quality materials
• Backed by Sierra's limited lifetime warranty

OEM Cross References: Replaces Mercury/Mercruiser 806612T, OMC 3850357, Volvo Penta 3850357 and 22024631, Pleasurecraft Marine R020027, and Mallory 9-33503. This genuine Sierra replacement knock sensor delivers reliable performance for Mercruiser, OMC, and Volvo Penta stern drive applications with GM small block engines.

Note: This sensor is designed specifically for small block V-8 engines and is not compatible with GM big block engines.