Sierra 18-5108 Pick-Up Coil Sensor, Replaces 811639, Fits V4/V6/V8 Delco EST Ignition

The Sierra 18-5108 is a pick-up coil sensor engineered for marine engines running a Delco EST ignition system. It is designed to fit V4, V6, and V8 engine configurations, generating the timing signal the ignition module relies on to fire the spark at the correct moment. As the pick-up coil ages or its magnetic winding degrades, engines can misfire, stall, or fail to start; replacing it with the 18-5108 restores a clean, accurate timing signal.

Built with a metal and plastic housing, the 18-5108 uses a flange mount for a secure, repeatable installation and produces a digital output signal. It carries an upper temperature rating of 400 degrees Fahrenheit, reflecting the heat exposure typical of an engine bay. Sierra engineers this sensor to meet or exceed the specification of the original equipment part it replaces, and Sierra supplies OEM engine manufacturers and boat builders with parts daily, so the 18-5108 is built to the same fit, form, and function as the factory sensor.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-5108
• Product Type: Pick-Up Coil Sensor
• Fitment: V4/V6/V8 engines with Delco EST ignition
• Replaces: 811639
• Material: Metal, Plastic
• Mounting Type: Flange Mount
• Output Type: Digital
• Upper Temperature Rating: 400 Degrees Fahrenheit
• Dimensions: 0.39 x 0.39 x 0.39 inches
• Weight: 0.09 pounds
• UPC: 030999563675

Fitment

• V4/V6/V8 engines with Delco EST ignition

Replaces (OEM)

• 811639

Frequently Asked Questions

What engines does the Sierra 18-5108 pick-up coil sensor fit? It fits V4, V6, and V8 engines equipped with a Delco EST ignition system.

Does the 18-5108 replace OEM part number 811639? Yes, the Sierra 18-5108 pick-up coil sensor replaces OEM part number 811639.

What is the pick-up coil sensor made of? The 18-5108 is constructed of metal and plastic for durability in the engine environment.

What temperature can the 18-5108 sensor withstand? It carries an upper temperature rating of 400 degrees Fahrenheit, suited to the heat inside a marine engine compartment.

How is the 18-5108 sensor mounted? The Sierra 18-5108 uses a flange mount for installation onto the distributor or ignition housing.

What type of signal output does this sensor produce? The 18-5108 pick-up coil sensor produces a digital output signal to the ignition module.

What are the physical dimensions of the 18-5108? The sensor measures 0.39 x 0.39 x 0.39 inches.

How much does the Sierra 18-5108 weigh? It weighs 0.09 pounds.

Is the Sierra 18-5108 an OEM-quality replacement? Sierra engineers the 18-5108 to meet or exceed the original equipment part it replaces, and Sierra supplies OEM engine manufacturers and boat builders with parts.

Will the 18-5108 work with a Delco HEI ignition setup? The 18-5108 is built for Delco EST ignition on V4/V6/V8 engines; confirm your ignition type matches before ordering.

What symptoms indicate a failing pick-up coil sensor like the 18-5108? A worn pick-up coil sensor commonly causes misfiring, stalling, or a no-start condition because the ignition module no longer receives an accurate timing signal.