Sierra Ignition Coil 18-7493, Replaces Mercruiser 392889925, Fits 4.3L 5.0L 5.7L 6.2L with 555 ECM

The Sierra 18-7493 is a replacement ignition coil engineered to meet or exceed OE manufacturer specifications for quality and performance. It fits 2001 and newer 4.3L, 5.0L, 5.7L, and 6.2L marine engines equipped with a 555 ECM, serial number OM300000 and up. This coil directly replaces OEM part number 392889925, making it a straightforward swap for boat owners servicing their ignition system.

Sierra builds this coil with a high-temperature dielectric epoxy that helps prevent moisture intrusion and thermal breakdown, two of the most common causes of ignition coil failure in a marine engine bay where heat and humidity are constant. The coil is constructed from high-grade materials for extended service life and consistent spark performance, and it uses a male connector for a secure, bolt-on installation. A failing ignition coil can cause hard starting, engine misfires, rough idle, or a complete no-start condition, so replacing it with a properly specified part like the 18-7493 helps restore reliable ignition system performance.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-7493
• Product Type: Ignition Coil
• Fitment: 2001 and newer 4.3L, 5.0L, 5.7L & 6.2L with 555 ECM (OM300000 and up)
• Connector Gender: Male
• Installation Type: Bolt-On
• Weight: 0.64 pounds
• UPC: 808282295004
• Replaces (OEM): 392889925

Fitment

• 2001 and newer 4.3L, 5.0L, 5.7L & 6.2L with 555 ECM (OM300000 and up)

Replaces (OEM)

• 392889925

Frequently Asked Questions

What does the Sierra 18-7493 ignition coil replace? The Sierra 18-7493 directly replaces OEM ignition coil number 392889925.

What engines does the 18-7493 ignition coil fit? It fits 2001 and newer 4.3L, 5.0L, 5.7L, and 6.2L marine engines equipped with a 555 ECM, serial number OM300000 and up.

Is the Sierra 18-7493 a direct bolt-on replacement? Yes, the 18-7493 is a bolt-on ignition coil with a male connector, designed to install in place of the original coil without modification.

How much does the 18-7493 ignition coil weigh? The Sierra 18-7493 ignition coil weighs 0.64 pounds.

What is the UPC for the Sierra 18-7493 coil? The UPC for the Sierra 18-7493 ignition coil is 808282295004.

What material protects the 18-7493 coil from moisture and heat? A high-temperature dielectric epoxy seals the 18-7493, helping prevent moisture intrusion and thermal breakdown in the marine engine environment.

Will the 18-7493 work on my boat if I do not know my ECM serial number? Confirm your engine has a 555 ECM with a serial number of OM300000 or higher before ordering the 18-7493, since fitment is tied to that serial range.

Does the 18-7493 include mounting hardware? The 18-7493 ships as the ignition coil itself; no additional components are included.

Is the Sierra 18-7493 genuine OEM or aftermarket? The 18-7493 is a Sierra-branded aftermarket ignition coil engineered to meet or exceed OE manufacturer specifications, not an OEM-branded part.

What symptoms indicate I need to replace my ignition coil with a part like the 18-7493? Hard starting, engine misfires, rough idle, or a no-start condition are common signs of a failing ignition coil, and installing the 18-7493 restores a coil built to the correct 555 ECM fitment.

What connector type does the 18-7493 use? The Sierra 18-7493 ignition coil uses a male connector.